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Midwestdrifter
04-09-2017, 01:31 AM
Good morning everyone. Since arriving in Australia I have been mulling about ideas for getting 4WD onto our van. I recently had some inspiration, and I would like feedback from those knowledgeable. As of yet I have not gotten into the research, mostly because I don't have regular enough internet access.

Here is the gist of it. Starting with our 2WD automatic T1N sprinter. Install front subframe, uprights, diff, axles from a 4WD.
On the rear, swap in the locking Rear axle from the same donor 4WD sprinter (is available).
Getting drive power to the new front diff is the challenge. I propose using the transfer case from an automatic 4WD ML series. The guys at vancompass used the same on their ongoing T1N 4x4 prototype.
Custom parts needed: Front Drive/Prop shaft, Rear drive shaft?, Some transmission and related mounts. Vacuum lines /wiring for dif locks. A switch and wiring for the ML high low transfer case.
Pros: Minimum modification to vehicle, retains stock transmission, engine, No messing with Canbus.
Cons: Full Time 4WD only, Low range only usable with 1st gear, Front diff longevity with 40% torque split? No 4WD traction control (it may be possible to swap in the 4WD ABS unit and controller? Axle ratios must match, and may require programming the ABS/ESP controller?

My concerns: Will the front diff handle full time AWD use? Clearance for the front driveshaft? Random ESP/ABS issues in 4WD mode?
Questions I need to answer
What is the factory torque split on the T1N 4WD?
Does the ML use CV or U-joint drive shafts?
Will the transfer case clear the fuel tank?

Another idea, which I have not researched at all, would be to use the NCV3 NAG1 4WD transfer case, which could offer selectable 4WD with high/low range.

The other options, such as swapping the complete drivetrain from a 4WD sprinter have many unknowns, and would likely be more labor intensive. Plus, all they have is right hand drive units over here!

Any feedback is welcome.

OldWest
04-09-2017, 05:41 AM
Before doing anything, might want to contact your shipping company to see if they might give you info as to modifications to a vehicle while abroad (other than maintenance).

If one thinks like a tax agency or an auto regulator, one might want to make sure to get any customs on the value of the mods and any regulatory approval on the mods (pollution, safety, etc.)? Does one need to sign any certifications re vehicle when returning to USA?

No idea if any of the above are issues, but got to figure somebody has thought about this.

Maybe check over at Expedition Portal community to see if anybody had to change to a different engine (maybe non-US spec engine) or made significant mods while overseas (accident, etc.), and then returned to USA.

The USA 25/26 year import rule and gray car import regs may be helpful, whatever they are.

P.S. How about getting a kangaroo bullbar too? Apparently, Australian roo bars are designed with the Sprinter safety features in consideration, as well as pedestrian safety.

Tooth Fairy
04-09-2017, 06:55 AM
:thinking: Ive traveled most of outback Aus in a 2 wheel drive, and mostly on dirt roads.

The only reason I bought my 4x4 was so I could access the more remoter areas, not something I would advise a newby to Aus to try.

As for the conversion, forget it, you will create more issues than you think, just buy a 4x4 and use that, Eric has a few for sale I think.

jackbombay
04-09-2017, 02:10 PM
...

Aren't you kind of past GVWR currently? So adding far by far will put you that much farther past GVWR?

Aqua Puttana
04-09-2017, 02:35 PM
My first thought was service after you are back in the good ole US of A. Will any parts be available once you are home?

Have fun. vic

lindenengineering
04-09-2017, 03:27 PM
My first thought was service after you are back in the good ole US of A. Will any parts be available once you are home?

Have fun. vic

I can answer that with a Big NO!
Dennis

DieselFumes
04-10-2017, 04:07 AM
Other issue is fitting in that shipping container for the return trip - does the 4x4 add height on a T1N? It does on the NCV3.

Midwestdrifter
04-10-2017, 05:20 AM
Before doing anything, might want to contact your shipping company to see if they might give you info as to modifications to a vehicle while abroad (other than maintenance).



Technically we are not supposed to "modify" the vehicle while it is in the country. Of course they are very vague about what modify means. We are allowed to make repairs and add accessories. At this point I am not thinking of doing the work in Australia. Just obtaining the parts would be my main goal, they could be palletized and shipped to the USA.

I did consider just installing the bolt on parts (axle and subframe) in Australia. Then leaving ALL of the custom stuff for when we have a long downtime. Again, I am just in the brainstorming stage currently.

:thinking: Ive traveled most of outback Aus in a 2 wheel drive, and mostly on dirt roads.

The only reason I bought my 4x4 was so I could access the more remoter areas, not something I would advise a newby to Aus to try.

As for the conversion, forget it, you will create more issues than you think, just buy a 4x4 and use that, Eric has a few for sale I think.

I am firmly in the "4WD is overrated for most" club. The only major needs we have for 4WD are for deep-ish sand/mud/snow. We also plan on doing some winter touring in mountainous states farther down the road (south america, Rocky mountains USA etc. So if 4WD can be done for a reasonable cost and effort, It is worth consideration I think. Plus, I am a gearhead at heart, and odd/custom doesn't scare me (much). Obviously I am considering the route that produces the lest amount of custom parts. In theory only a handful of custom bits would be needed.

Aren't you kind of past GVWR currently? So adding far by far will put you that much farther past GVWR?

With full everything plus jen and I we are about 100-200lbs over GVWR. The weight is well distributed, and we are well under the max axle loads. The Fox shocks make the weight much less noticeable (these vans carry a lot!) A rough estimate has the 4x4 bits adding around 200lbs? I would need to see what the 4x4 GVWR is, as swapping suspension bits and brakes may change it up or down. Depending on what the weight penalty is we can work out if its feasible.

My first thought was service after you are back in the good ole US of A. Will any parts be available once you are home?


Definitely a consideration. The 4x4 uses *many* of the same parts as the 2wd version. The struts are the same, steering rack and many of the bushings are the same. Big differences are the brakes and bearings on the front. The rear 4x4 axle uses the same brakes (i think). Obviously I would need to get a few spare bits for the front 4x4 bits to keep on hand. Still more research to do.


Other issue is fitting in that shipping container for the return trip - does the 4x4 add height on a T1N? It does on the NCV3.

I need to do some measurements on the 4x4. Since my van is lifted 2" already, I do not think the 4x4 bits will change its current height by much. As the van sits, I really can't get it any lower with shipping wheels and not have it drag on the ground.

TigerRecovery
04-11-2017, 08:02 AM
I've got a factory 4x4 T1N, it is significantly taller than a standard T1N. It's got part time 4wd with the transfer box also including a clutch to engage the front axle. Most of the time, I'm in 2WD and only need 4WD when I'm towing rally cars on loose surfaces in forests, I get too much wheel spin from the rear.

I've used low range on it and also locked the rear axle on the odd occasion off road, but only because one of the rear wheels was about 4 ft off the ground. If it had had coil spring suspension or more articulation, it wouldn't have been such an issue, but the leaf springs are very stiff.

Midwestdrifter
04-12-2017, 01:31 AM
I thought I would post some details on the 4x4 system up.

Here is a photo of the front differential. From this (https://sprinter-source.com/forum/showthread.php?t=53470)thread.

http://up.picr.de/27338380le.jpg

Here is the front uprights.

http://up.picr.de/27720238sk.jpg

Here is the a view of the front subframe.

http://up.picr.de/27720256zw.jpg

Hard to tell, but it looks like the sprinter uses U-joints on both ends of the front driveshaft.


Here is what the ML transmission with integral transfer case looks like from this (https://sprinter-source.com/forum/showthread.php?t=46515)thread.

http://i292.photobucket.com/albums/mm28/desertbound85/PITA%20VAN/IMG_0787-2_zpsq9qqxvnf.jpg

It uses a u-joint on the transfer case side, and a CV joint for the ML front diff.

It looks like it all clears the sprinters major structural bits.

http://i292.photobucket.com/albums/mm28/desertbound85/PITA%20VAN/IMG_0824-2_zpshdtkxwsg.jpg

The rear driveshaft will definately need to be custom. On my 144" van the central carrier will probably need to be moved or removed?

Looks like the fuel tank fits as well. Woot!

http://i292.photobucket.com/albums/mm28/desertbound85/PITA%20VAN/IMG_0974-2_zpsntftthfh.jpg

The Factory 4x4 uses drop spacers on the trans crossmember to clear the front driveshaft, as the transfer case puts it fairly low.

http://up.picr.de/27348643ky.jpg

The ML trans/case puts the front shaft higher and in front of the fuel tank, so smaller or possibly no spacers will be needed, the factory cross member may worth with minor modification?

It does look like the front 4x4 subframe can be installed without doing any modifications (bolt on).

Aqua Puttana
04-12-2017, 01:43 AM
:thumbup:

I suggest that you may want to modify your forum signature.


2004 T1N | Overland Conversion in Process Completed |


2004 T1N | Overland Conversion in Process Completed? |

Have fun.

vic

Midwestdrifter
04-12-2017, 02:05 AM
:thumbup:

I suggest that you may want to modify your forum signature.



2004 T1N | Overland Conversion in Process Completed? |

Have fun.

vic

:lol:

For some folks, its never finished...


There, fixed it for you. :shifty:

2004 T1N | Overland Conversion in Process Completed...For now... | 118,XXX miles | 140" | High Roof | My Build Thread (http://sprinter-source.com/forum/showthread.php?t=41215)
Another Random Blog | http://vagariesabound.blogspot.com

jackbombay
04-12-2017, 04:37 AM
For some folks, its never finished...


It's only finished once it been picked over in the junkyard for a few months :bounce:


Seems like it should all go together fairly painlessly :rad:

Tooth Fairy
04-12-2017, 08:49 AM
Buying parts for Sprinters in Aus is 4 times dearer than the rest of the world, why would you want to do that? :thinking:

OldWest
04-12-2017, 10:15 AM
Can't buy 4x4 parts in USA or from Europe/internationally to ship to USA. Apparently, Daimler may have agreements with various suppliers not to send 4x4 parts to USA.

T1N and most NCV3 Sprinters in USA were only two wheel drive and no 4x4 Sprinters until 2015 or so.

Even certain factory tools to fix Sprinters were not made available to American dealers.

Even posters here have not been successful in getting the nice Australian roo bars/bullbars shipped to USA (or at least no postings here so far of any success).

Midwestdrifter
04-13-2017, 02:18 AM
Buying parts for Sprinters in Aus is 4 times dearer than the rest of the world, why would you want to do that? :thinking:

Obviously I would be evaluating cost if I go forward. Wrecked or otherwise undriveable 4x4 T1N could yield reasonably priced parts.

If I were to obtain the parts (used) from Europe, I would have to pay someone else to source them, strip them from the vehicle, and palletize+freight. The labor would be substantial. As I am already in Aus, I can do all that myself. Plus I can personally evaluate the quality, and make sure all the necessary bits are there (bolts and hardware for example).

Obviously spare wear parts would need to be obtained. If I decide to move forward, I will search EPC for the relvant part numbers, and see which ones are not available in the USA. From there I can evaluate the cost. :idunno:


I just realized I have not confirmed if the ML Tcase turns the right direction for the T1N front diff. That would be a deal breaker!

Midwestdrifter
04-13-2017, 02:57 AM
Here are some more details on the M class Tcase from this (http://4x4abc.com/ML320/ML_specsIII.html)site. it appears to be down, so I used the internet archive to find a saved copy.

I have attached them to this post.

Midwestdrifter
04-13-2017, 03:50 AM
After doing some measuring, it looks like the fuel tank will need to be moved back about 6" to clear the Tcase. No mods to the tank itself, but new mounting straps will be needed, and a bracket as well. Extending the fuel lines should be simple.

Definitely adds additional and unwanted work. :frown:

Desertbound
04-13-2017, 08:19 PM
Cool idea. How expensive are the 4wd front components in Australia? If you're planning to use the ML transmission, I assume you would swap in the 4wd transmission too? It's not a divorce transfer case like the 4x4 T1N sprinter one is so you would have to put the ML's 4x4 transmission in too.

Also, the ML t-case is clocked up much higher than the Sprinter T-case is so front driveshaft angles may become an issue.

The ML front diff used a Rezeppa style joint at the diff and a standard 1310 CV at the t-case. I eliminated the Rezeppa in favor of a 1310 joint but this was not a straight forward conversion due to the pinion flange on the front diff. The pinion flange on the T1N Sprinter front diff is different and looks like it would be easy to source a 1310 companion flange that bolts up.

The gas tank will definitely need to be moved back and the wiring / plumbing to the tank needs to be extended. We moved the tank back about 12" on the Pita Van. Was pretty straight forward in the grand scheme of things.

Midwestdrifter
04-16-2017, 01:07 AM
Cool idea. How expensive are the 4wd front components in Australia? If you're planning to use the ML transmission, I assume you would swap in the 4wd transmission too? It's not a divorce transfer case like the 4x4 T1N sprinter one is so you would have to put the ML's 4x4 transmission in too.

Also, the ML t-case is clocked up much higher than the Sprinter T-case is so front driveshaft angles may become an issue.

The ML front diff used a Rezeppa style joint at the diff and a standard 1310 CV at the t-case. I eliminated the Rezeppa in favor of a 1310 joint but this was not a straight forward conversion due to the pinion flange on the front diff. The pinion flange on the T1N Sprinter front diff is different and looks like it would be easy to source a 1310 companion flange that bolts up.

The gas tank will definitely need to be moved back and the wiring / plumbing to the tank needs to be extended. We moved the tank back about 12" on the Pita Van. Was pretty straight forward in the grand scheme of things.

By Tcase I mean Trans+case as you mention they are a single unit. I would be curious to know what it takes to put the Tcase section onto a sprinter NAG1 trans. The otuput shaft would be different, and possibly the internal stackup on the output bearing and rearward clutch pack would be different.

The front angle is a bit of a concern, I guess I will have to cross the bridge when/if I come to it. Worst case a CV joint would be required? I have little experience with driveline design unfortunately. U joints are usually required to be in the ~6 degree range?

Do you happen to know what direction the the ML front shaft rotates in forward? Assume viewing the shaft from behind looking forward?

Thanks for the info!

SprinterMechanic
04-25-2017, 12:03 AM
We Just Finished our 8th Conversion of a 2wd Sprinter to a 4x4 Sprinter. SUCCESS!!!! We will offer a conversion for Public, Parts, Labor and WARRANTY included but be prepared to spend over $20k. But it will be done and Price will go down as we get more Efficient.
Interested Email. Richard@sprinterstore.com in OREGON.

jackbombay
04-25-2017, 12:38 AM
We Just Finished our 8th Conversion of a 2wd Sprinter to a 4x4 Sprinter. SUCCESS!!!! We will offer a conversion for Public, Parts, Labor and WARRANTY included but be prepared to spend over $20k. But it will be done and Price will go down as we get more Efficient.
Interested Email. Richard@sprinterstore.com in OREGON.

With Sprinter drivetrain parts from overseas?

Riptide
04-25-2017, 04:02 PM
We Just Finished our 8th Conversion of a 2wd Sprinter to a 4x4 Sprinter. SUCCESS!!!! We will offer a conversion for Public, Parts, Labor and WARRANTY included but be prepared to spend over $20k. But it will be done and Price will go down as we get more Efficient.
Interested Email. Richard@sprinterstore.com in OREGON.

Where are these lucky owners?? Where's pictures?? Richard, you just may have made my day. E-mail inbound when I get home tonight...

SprinterMechanic
05-03-2017, 12:20 AM
Where are these lucky owners?? Where's pictures?? Richard, you just may have made my day. E-mail inbound when I get home tonight...

I am tracking one of them down in Alaska, the best place to be test and well we haven't heard from them in so long i would say its a successful one,

Another one California, and and. I am learning that no one really thought of documenting this for the future, but i am sifting thru old files of over the last 10+ years of these.
I am pulling all the records and compiling a Documentary/Reference/Resume pictures, and hopefully lots of video and interviews of all that has been done, so maybe my 8 was off, as of now i can only possibly confirm 5 leads, so you got me, i was really excited and was going by what we could call fish stories from mechanics.

Lets say 5 for now, but I havnt talked to the Staff that is no longer working for us yet.
lots of pics on old computers too. i will find, yes yes (yoda voice)

autostaretx
05-03-2017, 02:07 AM
When i attended a PNW Sprinterfest down at SprinterStore/Upscale Automotive, they had two 2wd-to-4wd conversions in process up on the lifts.

I'll see if i can find the photos i took... (egad.. that was years ago...)
As i foggily recall, i think they used US-brand (i.e. Jeep, GM) chunks for part of the conversion

--dick

owner
05-03-2017, 12:00 PM
I would be curious to know what it takes to put the Tcase section onto a sprinter NAG1 trans.
That can't be done. The trans is a one piece casting, and the sprinter casting doesn't have the mounting points for the tcase. You would need to either use the ML trans and tcase as-is, or pull the guts out of the sprinter trans and put them into an empty ML trans housing. I believe the output shaft coupling can be changed over.

Option one isn't viable because we do know that the sprinter trans is much heavier duty than the ML trans, even the OM612 powered ML270 trans. eg the K1 clutch pack is 6 plates in the ML270 and 10 plates in the sprinter. Also we haven't confirmed yet whether the sprinter and ML even have the same gear ratio set. There are 2 different sets, large NAG1 and small NAG1. You wouldn't be able to interchange these. We can test this by putting a sprinter TCU into one of Eric's scrap ML270s or vice versa, we just haven't got round to trying it. If the TCU doesn't give any slippage errors, then we know they are the same ratios.

I saw you asked about running the sprinter front diff in AWD mode, it should be ok because there were AWD versions of the 4x4 T1N available. And I'd guess they used the same front diff. Would need a VIN lookup of a AWD sprinter to be sure so we can see the diff part numbers. Actually these have been posted in the AU section recently.

Which brings up the next point...

The ML tcase has a fully open diff. Couple that with the sprinters open front diff, and (poorly ASR controlled) open rear diff, and you won't be going very far offroad. A RWD sprinter would go further. With ML tcase all it would take is for one of your front wheels to break traction or become airborne, and then you would be stuck as all the torque would go to that wheel.

You would need to use the ABS controller from a ML270 to get the 4WD function (its like ASR but on all 4 wheels). Not sure what other systems would think of that, but it could be tested out before hand with a bit of work. Or you would need to somehow lock the ML centre diff. I think Eric has had a look at locking it before, but put it in the too hard basket. I know when the ML was new they ran one in the Dakar rally production class and they locked the centre diff somehow.

Midwestdrifter
05-03-2017, 12:17 PM
That can't be done. The trans is a one piece casting, and the sprinter casting doesn't have the mounting points for the tcase. You would need to either use the ML trans and tcase as-is, or pull the guts out of the sprinter trans and put them into an empty ML trans housing. I believe the output shaft coupling can be changed over.

Option one isn't viable because we do know that the sprinter trans is much heavier duty than the ML trans, even the OM612 powered ML270 trans. eg the K1 clutch pack is 6 plates in the ML270 and 10 plates in the sprinter. Also we haven't confirmed yet whether the sprinter and ML even have the same gear ratio set. There are 2 different sets, large NAG1 and small NAG1. You wouldn't be able to interchange these. We can test this by putting a sprinter TCU into one of Eric's scrap ML270s or vice versa, we just haven't got round to trying it. If the TCU doesn't give any slippage errors, then we know they are the same ratios.

I saw you asked about running the sprinter front diff in AWD mode, it should be ok because there were AWD versions of the 4x4 T1N available. And I'd guess they used the same front diff. Would need a VIN lookup of a AWD sprinter to be sure so we can see the diff part numbers. Actually these have been posted in the AU section recently.

Which brings up the next point...

The ML tcase has a fully open diff. Couple that with the sprinters open front diff, and (poorly ASR controlled) open rear diff, and you won't be going very far offroad. A RWD sprinter would go further. With ML tcase all it would take is for one of your front wheels to break traction or become airborne, and then you would be stuck as all the torque would go to that wheel.

You would need to use the ABS controller from a ML270 to get the 4WD function (its like ASR but on all 4 wheels). Not sure what other systems would think of that, but it could be tested out before hand with a bit of work. Or you would need to somehow lock the ML centre diff. I think Eric has had a look at locking it before, but put it in the too hard basket. I know when the ML was new they ran one in the Dakar rally production class and they locked the centre diff somehow.

Very good info, thanks. I was also thinking about using a 4x4 sprinter T-case, basically the complete drivetrain, minus engine/trans. Obviously the Tcase would need to controlled somehow, and a 4x4 fuel tank would be needed.

The open center diff is definitely a concern. I don't plan on any hardcore offroad, but lack of traction control on the front axle could be a deal breaker. If the 4x4 sprinter ABS module would run without issue, that would be ideal.

I am leaning more toward transplanting the 4x4 sprinter drivetrain from the Tcase to the wheels. Other than controlling the Tcase, and possible ABS integration, there would be no modifications to factory harness, and thus less chance of a software issue. A custom driveshaft from the trans to Tcase would be required.

Regarding the ML NAG gear ratios, the Vancompass guys have a sprinter running a 4x4 setup out of an ML. They used the ML trans/tcase assembly with the sprinter TCM and valve body. So at least some of the ratios are the same. Not that I am considering doing this, but it it might be possible to rebuild a sprinter NAG inside a ML trans housing.

owner
05-03-2017, 12:32 PM
Regarding the ML NAG gear ratios, the Vancompass guys have a sprinter running a 4x4 setup out of an ML. They used the ML trans/tcase assembly with the sprinter TCM and valve body. So at least some of the ratios are the same. Not that I am considering doing this, but it it might be possible to rebuild a sprinter NAG inside a ML trans housing.
That is good info, yes me and Eric would be looking to transplant the Sprinter NAG1 guts into one of our MLs next time a ML trans dies. Would be good to get the stronger internals.

As for the sprinter front diff AWD vs 4x4, I have found 2 NIN numbers for you. Unfortunately the lookups dont specify the part number for the front diff, but the VINs can be used with EPC to find the part numbers...

T1N 4x4 part-time 4x4 with diff locks (ZG3 SA code)...
http://carinfo.kiev.ua/cars/vin/mercedes/vin_check?su=eckkrg-g

T1N AWD (ZG1 SA code)
http://carinfo.kiev.ua/cars/vin/mercedes/vin_check?su=18-8dg2p

I still think the ML tcase with the sprinter front diff and AWD sprinter ABS module (or ML ABS module) would work well. You could find out the AWD sprinter ABS part number the same way as above. The problem with the part-time 4x4 sprinter is the constant noise from the remote tcase bolted to the floor. Having the ML integrated tcase should make it a lot quieter. The ML also has a super low low-range gear, like 16:1 on 1st gear overall iirc.

PS Not sure why you think you would only have 1st gear in low range? The ML shifts through all the gears (rather quickly lol) when in low range. EDIT: I see now from that other thread, they are doing this to prevent the electronics from freaking out. I don't see why they can't just wire up the MLs AWD control box into the sprinter CAN? Coupled with the ML ABS controller it should all just work as if it thinks its in an ML.

PPS i can help you with a 4x4 fuel tank. We could swap your 100l US tank with my 96l 4wd tank. Win/win

owner
05-03-2017, 01:11 PM
Regarding the ML NAG gear ratios, the Vancompass guys have a sprinter running a 4x4 setup out of an ML. They used the ML trans/tcase assembly with the sprinter TCM and valve body. So at least some of the ratios are the same. Not that I am considering doing this, but it it might be possible to rebuild a sprinter NAG inside a ML trans housing..

Ahh wait, I just read that thread, and they used an ML430 donor. That is a V8 powered car, and from what I've read all MB V8's apparently use the "Large NAG1" ratio set. So we are still none the wiser except that from what they posted the Sprinter looks like it may also use the "Large NAG1" ratios. I'm pretty sure the ML270 uses the small NAG1 its a 722.661. I will get round to testing it one day at Erics by simply swapping TCUs and seeing what happens. Its just the ratios BTW, the casing is the same, they just call it large/small for some weird reason.

Midwestdrifter
05-06-2017, 02:39 AM
Regarding the gear ratio question. I believe the only module that has any visibility of gear ratios in the trans in the TCM. In theory, as long as the TCM program matches the trans, there won't be any slippage errors.

Doing some reading in the function description in the workshop manual(s), It seems like many of the T1N modules don't do much complicated bi-directional communication with the others. The TCM for example gets request throttle date from the ECU, and speed data from the ABS/ESP controller, and it reports current gear over canbus. However, are these mostly regular broadcasts over CAN? Or are they requested by a specific module? I believe they are regular broadcasts. If this is the case, and the broadcasts conform to a standard (same address/header data) then swapping modules from other versions of the T1N should in theory not cause compatibility issues. This applies specifically to the 4x4 ABS/ESP module.

The other question is how the modules are addressed on the CANbus. At startup the ECU/Cluster etc are looking at the canbus to see what modules are connected. If some are missing, they will report a relevant error and/or CEL. Are all sprinter ABS modules addressed the same? Do they announce or report their identity using the same "name". My experience with other vehicles, and my reading suggests that they do in general.


Another question I need to answer, is how the Sprinter 4x4 transfer case is controlled. Which module handles it? In order to get four wheel traction control, the ABS controller must know that 4x4 is engaged.

I have been unable to located a factory service manual for the 4x4, if anyone has one, please post it up!

owner
05-06-2017, 05:27 AM
Yep the internal CAN frames are usually continually broadcast at rate. The CAN ID of the frame says which module (node) it has come from. The IDs of the frames from each node are all hard coded, so they rarely change for the same era of car. So I would go further and say that the t1n and ml270 abs, TCU, 4wd box are all compatible. I know for a fact that the abs module sends the same CAN frames for both of these.

I'd say the 4wd abs module looks for a CAN frame from the 4wd controller, so it knows when it needs to switch to 4wd program. The TCU must do the same so it knows when low rage is selected.

I reckon you could use the abs, TCU, and 4wd controllers from a ml270 in the sprinter. The tcu shift patterns and tc lockups will be different than the sprinter. Otherwise you'd need those controllers from an awd 722.6 sprinter, which might be hard to find.

Midwestdrifter
05-06-2017, 08:00 AM
I am not sure if the ML270 CDI was available in the USA, but it is possible the gasoline versions TCM/TCU would work, just with different shift points?

Which makes me wonder if the ML430 NAG1 doesn't use the heavier internals due to the extra HP/torque.

So it looks like either the AWD-Automatic hybrid using ML parts, or the part-time 4WD-auto using sprinter parts would both be possible.

Thanks again for posting, very helpful. :thumbup:

owner
05-06-2017, 11:34 PM
Yeah you never got the ml270. I'm fairly certain the V8 ml's use the large nag1, and the v6 and I5 use small nag1. Shift points for a petrol TCU will be crap for the sprinter I reckon. All is not lost though, there is the ml400 in Europe, which is a v8 CDI and uses large nag1 gearing. I have seen these tcus for sale on eBay.

Midwestdrifter
06-04-2017, 03:07 AM
Howdy folks. Been giving this some though on the long drives in WA. Managed to get the van stuck a few times since. Both times an air down, and bit of creative driving got us out. Of course we turned around at that point!

Pending a financial review and a few hours measuring/inspecting a 4x4 T1N, I believe the route I would take is the part time 4x4 with low range using a the transfer case and axles from a 4x4 T1N.

My basic premise would be to acquire the parts in Aus. I would install the axles, but retain the factory rear driveshaft and ABS/wiring etc. In theory this would be a simple bolt on (minus an axle ration program change), and adding a vacuum solenoid for the rear locker would be simple. The transfer case, 4WD controller, ABS module, fuel tank, etc from the 4x4 donor would be shipped in a crate to the USA, where it would await our return.

Ideally I would be able to get the low range working in all 5 forward gears using the factory controller (buttons on dash), as well as the 4x4 ABS/traction control. This might be possible with a ML270/400 TCM, I am okay with low range in 1st gear only if it comes to that (basically a crawler gear).

I need to confirm the bolt-on fitment of the axles, and the ride height, as the van will need to fit back into a container.

Pros:
Access to donor vehicle for measuring, and can ensure all needed parts are pulled with care.
A locking rear axle would be helpful, even with 2WD.
Down time in Aus would be minimal (a few days hopefully)

Cons:
No 4WD for remainder of trip (not a big deal).
Shipping of parts to USA adds cost.
Parts availability for 4x4 specific bits.
Might require a custom rear driveshaft once Tcase is fitted, as 140" WB 4x4 T1Ns may not be available.

jcmadeintheshade@gmail.com
06-04-2017, 07:07 PM
Try to impress upon Smart Bar while you are there, to bring some to the USA market. I have never seen or maybe missed the price listed. Any idea how much they cost over there in the land of OZ? This would be nice to know for the T1n's and the NCV's, if there is any difference.

What a fantastic trip to ship your van there and back. The adventure of a lifetime. What's next? Thanks for the updates and to all here.

westyventures
06-04-2017, 08:09 PM
Can't buy 4x4 parts in USA or from Europe/internationally to ship to USA. Apparently, Daimler may have agreements with various suppliers not to send 4x4 parts to USA.



Ha, yes you can, I've done it, the full drivetrain minus engine. Customs doesn't care about old car parts.

Midwestdrifter
07-27-2017, 11:21 PM
Okay ladies and gents. I have had a chance to inspect a T1N 4x4. Some notes.

The 4x4 subframe and differential SHOULD fit with the NAG1 auto trans. It will be a close fit, but the manual trans is a close fit as well. This would make sense, as I believe the T1N was available in 4MATIC version in Europe? The tightest clearance is between the Diff input flange, and the shift cable mounting plate. Worst case scenario, the input flange could be turned down a small amount in a lathe.

The manual transmission is about 4" shorter than the Automatic transmission. The driveshaft between the Tcase and trans is about 10-12" long it has 2 u joints and a slip yoke. In order to use the auto trans and Tcase, this would need to be shortened to 6-8". From my reading this should be possible, as similarly short shafts are used on some USA domestic 4x4 modifications. :idunno: If the Tcase is left in the factory position, the other 2 shafts can be re-used. It may be possible to move the T-case back 4", but new shafts would be needed, and a custom mount made. This would lower the Tcase due to the frame tube at this location by about an inch, which would require adjusting the other driveline angles to match

The other option is to use the manual transmission. Which would require some custom ECU programming, etc. As a plus, the trans shift linkage appears to be long enough to swap the shifter to the left side if needed.

The 4x4 rear axle uses the same mounting provisions as the 2wd axle, and should be a bolt-on affair.

The Tcase mounts, and front subframe will also be bolt on. Some holes for the Tcase supports may need to be drilled, but they all use existing frame mounting locations.

The Tcase is vacuum actuated, and has position switches for sensors. In the event that the electronic control unit for the 4x4 doesn't work, manual vacuum control will be simple to implement.


The 4x4 ABS unit is physically the same, and mounts in the same location. It may have different internals though. The RHD brake lines are essentially the same after the ABS unit, so the 4x4 brake lines can be re-used.


The trans support member looks to be the same as the 2wd auto, but it is farther forward, and space down about 2.75" to clear the front driveshaft.

Absolute ground clearance will drop less than an inch I believe mostly due to the front subframe). The break-over angle shouldn't change either, as the fuel tank is still the lowest point. The T-case and trans support do stick down a bit farther than I would like, but thats the price of 4x4 without a bump in the floor.

I started an album here, and will upload photos as I take them.

https://flic.kr/s/aHsm1rikEt

Riptide
07-28-2017, 01:19 AM
Drifter, is that the single speed transfer case? Did you have a chance to drive the van you took pictures of? I wonder how a divorced case van with three driveshafts feels...

Midwestdrifter
07-28-2017, 01:33 AM
Drifter, is that the single speed transfer case? Did you have a chance to drive the van you took pictures of? I wonder how a divorced case van with three driveshafts feels...

2 speed transfer case. 1.4/1 low range. Haven't driven one yet. From my understanding, in 2wd mode, it feels the same as a normal van, with some added gear noise from the transfer case.

Mercedes/obraingers driveshaft layout is quite good, angles etc, I don't see.vibration being a concern.

wayne poulsen
07-28-2017, 02:43 AM
Hi Drifter.

I have a plan on a back burner to fit auto trans to my 2005 4x4.
The physical fit with a short CV jointed shaft seems to be OK. An auto dash would be good.
The main issue for me would be getting an auto ecu to work with the the 4x4 kit.

Two approaches would seem to me most hopeful for your project.

Manual trans....Get a 4x4 ecu, enabling compatability with traction control, low range, 4x4 functions. A manual dash and 4x4 instrument module would be good.

Auto trans...Keep your 2wd ecu. Manualise your low range,4x4, rear diff lock functions. Hence outside of ecu control. You would not get traction control on front axle . Much more able than what you have.

For my conversion the 4x4 ecu cant talk to an auto trans. But using a stock auto 2wd ecu (and manualising low range and 4x4 functions) would mean loss of traction control....Not for me, the TC is brilliant in 4x4 and not worth the advantages(?) of the auto.

Your auto option seems most doable to me.You're certainly in the right continent to source the bits and and pack them in for the return trip.

What custom ecu options are available to you?

Regards
Wayne
Fremantle

Midwestdrifter
07-28-2017, 10:02 PM
So, the ECU/ECM is not likely directly involved with the control of 4x4. It may supply relevant information in its CAN broadcasts, but that would likely be the same between 2wd and 4x4 ECUs. I need to confirm, but I believe the 4x4s use a seperate module for conotrol of the transfer case and rear diff. This module would report 4x4 status over canbus. The ABS controller would then switch to 4x4 mode. In theory, the ABS module and 4x4 module could be swapped into a 2wd, and still function.

If the tcase and diff are controlled by an existing module (such as the ECU) then this approach won't work.


The 2wd TCM does not like it when you run in low range, as it thinks the trans is slipping. The TCM gets its output shaft speed by reading the rear wheel speed sensors in the ABS modules Can Broadcasts. There are two possibilities here. First, if the 4x4 ABS module corrects the speed sensor values when in low range, the TCM will still function normally. The second option is to swap in a ML TCM used in the v8 diesel european spec units. These use the NAG1 large ration trans. If the sprinter 4x4 controller can frames are similar enough, the ML TCM will allow operation in low range. It is a bit of a stretch without further research though.

Low range will still function with the auto trans, but you will have to stay in first gear (basically a crawling gear).


In your case, going from a manual 4x4 to auto trans, you might have it a bit easier. In your case, it may be possible to install an auto trans, TCM, and gear selector. The difficulty will be with the neutral start switch, and if the ECU will do weird things if it thinks you are always in neutral? In theory, the ECUs CAN broadcasts will contain much (if not all) the same information in both the auto and manual versions. Whether or not it broadcasts them on the same CANbus segments is a question to be answered.

I am not sure, but communication between the TCM and ECU may not be bi-directional.? I need to sit down with the logical and CANbus diagrams for a few hours.

The final question, is whether or not the 4x4 ABS modules CAN broadcasts contain the necessary information for the TCM to calculate output shaft speed. Since the TCM program is not alterable, I would suspect that the axle ratio coding is done in the ABS module only?

Anyways, I am suggesting (despite my ignorance) that is may be possible to simply install a auto trans, TCM and shifter assembly into a 4x4, and have it work? Swapping clusters would also be desirable, so that you would have visibility of current gear.

In the end, the only way to be sure would be to patch into the relevant CANbus pairs, and temporarily wire in the TCM, Cluster, etc?


Edited: After reading the training materials, the TCM does use bi-directional communication with the ECU, specifically for LHM, TC status, and kickdown. I don't believe a manual ECU would work. That being said, an auto ECU and cluster may be the way to go. I don't have any training materials on the 4x4, so I cannot know for sure how the 4x4 is managed. Given the way the 4x4 kit is designed, I believe they would have taken a minimal intervention approach, in order to minimize programming and part needs.

The ABS/CAB/ESP control unit reports the conditioned wheel speeds over CAN. So a TCM capable of recognizing 4x4 low range would likely be needed for all 5 gears in low range.

Also, the 4x4 I have been looking at does not appear to Have ESP. I am not sure if an T1N 4x4s came with ESP at this point. The big giveaway is that the 4x4 ABS pump block (HCU) does not have a pressure sensor on the aft side. Our van has ESP, and has this sensor. Swapping to a 4x4 HCU and ABS controller would remove the ESP function.

wayne poulsen
07-29-2017, 03:45 AM
Thanks drifter
I am not literate in this whole electronic communication thing and your posts are very helpful.
My 4x4 has ASR , but not ESP.
Sprinter Operating Instructions (SOI) states..
"ESP is not available on vehicles with rear-axle lock or vehicles with permanent or engaging all-wheel drive."
Wayne

vanski
07-29-2017, 06:20 AM
Arduino or like to intercept signals, process, post back needed values to TCM and/or ECM???? Child's play for some folks I'm sure.

Of course in a real LHM situation this could be counter productive $$,$$$..

Midwestdrifter
07-29-2017, 06:39 AM
Arduino or like to intercept signals, process, post back needed values to TCM and/or ECM???? Child's play for some folks I'm sure.

Of course in a real LHM situation this could be counter productive $$,$$$..

A product called a can bridge can be used to relay relevant signals or modify frames if needed.

vanski
07-29-2017, 06:49 AM
A product called a can bridge can be used to relay relevant signals or modify frames if needed.

Theoretically you could 'can' as in 'trash' the need for other mbz control units since you could create your own? As in an mlxxx tcm? Still ramping up in this conversation; sorry for the ignorance. Just throwing out ideas which don't depend on the mother ship..

Midwestdrifter
07-29-2017, 10:03 PM
Making your own faux module would be very difficult. The exact details of MBs implementation of CAN are known only to a select few, and the learning curve would be insane, both from the software and hardware standpoint.

I have learned that early T1N 4x4s did not have traction control in 4x4 mode. Additionally ESP was not available ony any T1N 4x4s. There are several reasons for this.

First, ESP combines ASR, ABS, EBD (brake force distribution) and brake assist into one package. On non ESP vans, the ABS/pump module performed ASR, ABS, and rear axle traction control (except in 4x4 mode). These vans had a mechanical brake proportioning valve connected to the rear axle (our van does not). Swapping to a 4x4 ABS pump/module would remove this functionality from our van. The safety improvements from ESP, especially on a tall heavy van are substantial.

After driving an early 4x4 some, I believe I am okay without the traction control features of the later 4x4 T1Ns.

So at this point my final goals are as follows.

Install 4x4 axles, transfer case, and 4x4 module.
Push button for 4x4, low range, and diff lock
All forward gears in low range
ESP defeat switch

I believe the easiest route for getting the TCM happy would be to swap in a high ratio ML TCM. I am unsure if the 4x4 module sends the correct CAN info to trigger the low range program in the ML TCM (probably not). The next approach would be to use a can bridge between the TCM and CAN bus. The bridge would pass all traffic unmodified, except when in low range. In low range it would correct the wheel speed readings by 1.4 to prevent TCM soft LHM.


Wayne, could you provide some details on your proposed Trans-Tcase shaft? Are the Cvs plunge type?

wayne poulsen
07-30-2017, 04:14 AM
Hi drifter.
Time to give Eric E. a shout.
He has investigated the CV jointed trans-Tcase shaft as an early approach to fix 4x4 driveline noise by eliminating the need for precision alignment.
His proposal included two cv joints, he will have to describe them.
I think he has owned (and sold) an early 4x4 auto van with no ASR.
I am a huge fan of the 4x4 ASR and wouldnt give it up for anything else.
To each their own, and your proposal would certainly give your truck a hugely increased capability. What I find with the ASR is that it goes a long way to mitigating the offroad downside af a 140"wb van. I am very happy with having comparable mobility to a "standard" generic 4x4. ASR and 235/85x16s allow this.
Its interestng the convergence in this discussion and am willing you to victory.
Thanks also to owner.
Could you try a simple explanation of how the "bridge would function.
Ta
Wayne
Fremantle

Midwestdrifter
08-01-2017, 04:42 PM
I talked with Eric regarding the shortened shaft. Essentially its two plunge style CV joints (might be the same as the sprinter 4x4 front outers). Each has a machined adapter ring with countersunk holes to convert from 4 to 6 hole pattern. A custom short shaft would need to be made, but should be pretty straight forward for a shaft shop to machine one. It is definitely a good solution, and would help eliminate the precise alignment needed to prevent vibration. The CV wear might be faster in this application, it just depends on how the lower torque, but higher RPM operation affects it.

A can bridge is a microprocessor device that connects two CANbus segments. All the devices (modules) on each segment see every CAN frame unmodified. The bridge can be programmed to modify frames that pass through it (or block them). The difficult part is doing the programming, as most of these units do not have a low level user interface, and require some coding skills. There are some products that are more user friendly.

Thankfully the task would not be terribly difficult. Pass 99% of frames without change, and when in low range, modify the 4 integer values in the ABS frames for the wheel speeds to the correct amount. It would obviously require some understanding on the ID of the ABS module, and which bits in the frame are the wheel speed.

owner
08-02-2017, 10:34 AM
It would obviously require some understanding on the ID of the ABS module, and which bits in the frame are the wheel speed.
I have all of those CAN details already for the T1N somewhere, and the ML ABS module is identical in this respect. Its pretty easy to reverse engineer the wheel speeds, they are probably the easiest of the lot. I think I found rpm and gear position and a coupe of temperatures too on that bus. Your idea of doing a CAN bridge to modify the wheel speeds in 4WD mode is half done already...

I made an arduino style program for Eric several years ago that would read in and compare the 4 wheel speeds to try to detect a flat tyre when he was driving on rough roads. It even kind of worked. But it needed heavy software filtering because the difference in speed between an inflated tyre and a flat one isn't really that much. But it is enough that it can be detected reasonably quickly and probably save a tyre from being shredded.

That device only had the one CAN port though. But all the details are here somewhere. I did buy a device a few years ago called a CANTriple which has 3 CAN ports and a very simple interface for doing a your bridge once I tell you the frame ID and layout. I never ended up using mine but it looks like you can still get them. https://canb.us/

Midwestdrifter
08-02-2017, 08:24 PM
I have all of those CAN details already for the T1N somewhere, and the ML ABS module is identical in this respect. Its pretty easy to reverse engineer the wheel speeds, they are probably the easiest of the lot. I think I found rpm and gear position and a coupe of temperatures too on that bus. Your idea of doing a CAN bridge to modify the wheel speeds in 4WD mode is half done already...

I made an arduino style program for Eric several years ago that would read in and compare the 4 wheel speeds to try to detect a flat tyre when he was driving on rough roads. It even kind of worked. But it needed heavy software filtering because the difference in speed between an inflated tyre and a flat one isn't really that much. But it is enough that it can be detected reasonably quickly and probably save a tyre from being shredded.

That device only had the one CAN port though. But all the details are here somewhere. I did buy a device a few years ago called a CANTriple which has 3 CAN ports and a very simple interface for doing a your bridge once I tell you the frame ID and layout. I never ended up using mine but it looks like you can still get them. https://canb.us/

That is great news. It has been a very long time since I have done any microcontroller programming. :cry: Regardless, I should be able to cludge something together using the Arduino codebase and can-triple firmware. I can feel a headache coming on...

I will drop you a PM, and hopefully you can find your notes/code.

I wonder if the T1N 4x4 module uses the same ID/frame layout as the ML 4x4 controller? If so, the v8 Diesel ML TCM may still be an option for plug-and-play.


It would also be possible to have the can bridge send frames to disable ESP/ASR when 4x4 is engaged.

Cheyenne
08-02-2017, 09:27 PM
It would also be possible to have the can bridge send frames to disable ESP/ASR when 4x4 is engaged.

A quick way to 'turn off' the ESP/ASR when 4x4 was selected would be to substitute the four wheel speed signals with a common 'calculated' signal.
In other words, only when 4x4 is selected, transmit a corrected speed from one wheel to all four channels so the ABS ECU does not see any wheel spin or slip. In normal driving the CAN module would simply pass all four wheel speed signals through as actual values.

I hope that makes sense.
Keith.

Midwestdrifter
08-02-2017, 09:52 PM
A quick way to 'turn off' the ESP/ASR when 4x4 was selected would be to substitute the four wheel speed signals with a common 'calculated' signal.
In other words, only when 4x4 is selected, transmit a corrected speed from one wheel to all four channels so the ABS ECU does not see any wheel spin or slip. In normal driving the CAN module would simply pass all four wheel speed signals through as actual values.

I hope that makes sense.
Keith.

So you are proposing using a simulated wheel speed signal, and applying that to the ABS modules speed sensor wires?

Cheyenne
08-03-2017, 07:54 AM
So you are proposing using a simulated wheel speed signal, and applying that to the ABS modules speed sensor wires?

Basically Yes, but only when in 4x4 and not requiring ABS/ASR, etc.

At all other times simply pass through the true wheel speed signals to their respective input.

owner
08-03-2017, 02:23 PM
Basically Yes, but only when in 4x4 and not requiring ABS/ASR, etc.

At all other times simply pass through the true wheel speed signals to their respective input.
You could still use a microcontroller to do this, probably even the same one you're doing the CAN on. Would just need 4 CTM inputs and 4 PWM out. You could also then calibrate your speedo exactly how you want it with those big tyres you run.

Midwestdrifter
08-03-2017, 02:39 PM
You could still use a microcontroller to do this, probably even the same one you're doing the CAN on. Would just need 4 CTM inputs and 4 PWM out. You could also then calibrate your speedo exactly how you want it with those big tyres you run.

Having the wheel speed sensors routed through a micrcontroler (and software) may have an inpact on ABS/ESP operation. Mostly due to the latency in the software. That may be a can of worms you wouldn't want to open? It really just depends on the latency levels. Also the ESP calculates a dynamic friction value based on accelerometer values and wheel speed inputs.

Intercepting and modifying CAN frames should not cause the same problems, as the ABS/ESP?ASR processing is done by the ABS/ESP module, which doesn't relay on CAN frames for wheel speed data?

owner
08-04-2017, 04:14 AM
Yes but the ABS/ESP is the source of the wheelspeed CAN frames. You can modify them all you like on the bus but they won't change inside the source. Thats why it would need to be done on the signal wires into the ABS/ESP. Latency should be negligible if done right. Another bonus is you could also fix the ASR function...

You could make an optional switch so the 2 front wheels match the slowest rear wheel. That means the ASR will be applied to the fastest rear wheel as normal, but you could prevent the ecu from cutting engine power out from under the ASR. You might not even need 4WD then lol.

Midwestdrifter
09-13-2017, 01:26 AM
Update. I believe I have reached an agreement to part out a 316 T1N 4x4. I am still doing research, but we are getting closer.

My major hurdles.

#1 Find a dealer or similar to perform the SCN recode to 4.16 rear axle ratio. Owner indicates that some Chinese group will perform a encode remotely via a internet connected Star clone. This would still require me to drive the van to a location with decent internet though.

#2 Determine if my 16" steering rack is compatible with the 15" 4x4 suspension.

I am concerned that the 15" steering knuckles may have a different ratio, so the 15" racks may have different travel or gear ratio. If this is the case, a 16" rack may not fit, or may result in incorrect steering angle calculations.

I have recently discovered that is the steering wheel position sensor goes 5 degrees beyond its programmed "max" the sensor will lock out and disable many of the ESP functions.

#3 I need to do some miscellaneous measurements to ensure everything will fit as intended. I also need to make sure I won't end up with a incorrect ride height front to rear.

#4 I need to put the van on a weighbridge, but I believe I want to change up to a 416 (3500) series front spring. Which means sourcing a spring, and the pads/blocks for installing it.

Eric Experience
09-13-2017, 12:06 PM
MWD.
The 4x4 steering rack has about 40mm less stroke, in a previous conversion I turned up collars and fitted them on the rack to limit travel. Eric.

Midwestdrifter
09-14-2017, 02:08 AM
MWD.
The 4x4 steering rack has about 40mm less stroke, in a previous conversion I turned up collars and fitted them on the rack to limit travel. Eric.

Very helpful, thanks. Does this mean the 4x4 has less steering angle? Or are the lever arms just shorter to compensate?

I am not sure how the esp will behave with a different ratio of steering wheel to steering angle if that's the case. I suspect it will still work during normal driving. If seems to to tolerate a lift just fine. :shifty:

Riptide
09-21-2017, 04:59 PM
Are you having all this done in Australia? Am dying to see how you sort the computer thing out on a NAFTA Sprinter; it may prompt me to finally get started on my own conversion...

Midwestdrifter
09-22-2017, 01:19 AM
Are you having all this done in Australia? Am dying to see how you sort the computer thing out on a NAFTA Sprinter; it may prompt me to finally get started on my own conversion...

yes, at least partially. The plan is to stick with my auto trans and om647 engine. So I will be programming a custom interface for the TCM, which will sort out low range. I may be able to supply OM612 compatible 4x4 ECU, cluster, and skreem (manual trans) drop me a PM if you are interested.

There are some unknowns with the 2Wd ESP still.

Midwestdrifter
10-05-2017, 11:25 PM
A user posted a question about his sprintshift 4wd. The trans to tcase Shaft is shorter, maybe short enough for the nag5 auto trans?

https://sprinter-source.com/forum/showthread.php?t=59970

Midwestdrifter
11-06-2017, 02:55 AM
A rather abrupt end to this venture sadly.

After some very intensive measuring, I determined that the 4x4 front diff will interfere with the NAG1 trans pan. The interference is about 10mm, and may partially interfere with the main case where the pan attaches. Not a deal breaker for those with time and access to a shop for some rework. Moving the diff mounts slightly, and modifying the pan would likely allow use of this diff.

If the total risk (cost, time, etc) were not so high, I would likely consider doing the necessary modifications. But it is just too much to do in Aus, when we have deadlines for shipping and whatnot.


I also stumbled across some interesting info. There is/was an auto 4WD T1N sold in europe. It was very similar to the ML AWD setup. It uses a NAG married transfer case, and a ML front diff. The ML style front diff is not nearly as heavy duty as the manual 4x4 one, with the ring/pinion being about half the size. This allows it to clear the NAG1 trans. The remainder of the parts are basically the same as the manual 4wd version. There are some pictures on the link below (low resolution though).

https://www.sprinterstore.com/t1n-conversion/


I have learned a few more things that may help others. To my knowlege the only module that needs coded for an axle ratio sway is the instrument cluster. The axle ratio is interlocked, and listed under "K factors" a dealer, or someone with Mercedes SCN access is needed to change this.

The instrument cluster and ECM also can be coded for a automatic transmission, though the ABS/ESP module may need to be coded as well, again SCN coding is needed. In this way, it may be possible to put an Auto trans into a manual 4x4.


I see no reason why a 4x4 ABS module and 4x4 module cannot be installed and functioning in a 2wd auto sprinter. The ABS modules coding seems to be independent enough, based on my research and observations.

Also interesting, is that it appears that a manual trans can be fitted to an auto sprinter. Most of the parts are the same left/right hand drive. You would need to add a few wires for the clutch switch, and similar. Then perform SCN coding to change the ECM/Cluster/ESP to manual trans variants.

Midwestdrifter
08-12-2018, 12:28 AM
It been almost a year, and I am back with my recent thoughts. I would still like to do this conversion if I can swing the cost. Hopefully before our next major trip (2020?).


I have recently been looking at Jeep applications of the NAG1. The transmissions have a different main case which accepts a NV/NP integral transfer case. There a a large variety of these cases which share the same bolt pattern. The jeep version uses a 23 spline input shaft. The bolt patter looks symmetrical, so it may even be possible to clock the Tcase to lower the front output. Otherwise an adapter plate could be be fabricated to rotate the unit.

The NV200 series cases have several options. The unit stock on most cherokees uses an electric motor to switch between 4HI, 4Lo, and 2WD. A separate electrical clutch locks the center diff. Low range is 2.7:1.

There is several manual versions, with a lockable center diff as well. These would be operated by cable shift.


Does anyone know if oberaigner makes their own Tcase for the T1N conversions, or is it borg warner sourced?


My current thoughts are to procure a T1N factory 4x4 subframe (ideally in 1:3.73 ratio if possible). Then procure a Jeep NAG1 main case and compatible Tcase. NV247 or NV242 maybe?

I would then transfer my sprinters transmission internals, valve body, TC, and bell housing to the jeep case. The trans mount would need lowered to clear the front shaft (simple spacers). New driveshafts for front and rear would be needed. Possibly the Tcase output flanges would need swapped.

At this point a shift cable(s) or electronic control would need rigged up, and the vehicle could be driven. Low range would still need some electronic wizardry.


The main advantage of this approach is that the Tcase becomes a common part in the USA (and anywhere jeeps are sold). Mechanical control eliminates the needs for messing with sprinter electronics, or complex vacuum actuation.

The T case can be selected as needed for the application. Unlike most T1Ns, an open center diff option is available, as are limited slip center diffs. This is ideal for those who want winter traction, instead of off-road capability.

wayne poulsen
08-12-2018, 03:10 AM
Hi Mid
Glad to hear youre still working on the conversion idea.
Hope you manage it, I would still like to put a NAG1 in my manual 4x4 TIN.

You say "The instrument cluster and ECM also can be coded for a automatic
transmission, though the ABS/ESP module may need to be coded as well,
again SCN coding is needed. In this way, it may be possible to put an Auto
trans into a manual 4x4."

So a dealer or someone with Mercedes SCN access would be able to do this?

Jeep trans is interesting with the full time 4x4 and locking center diff options, all singing all dancing!
2.7 low range is also very attractive.

Would you still be needing to trim the auto trans pan?

I havent heard of 3.73 final drive in sprinter 4x4s?
4.1 with 235/85x16s working very well on mine

Did you get a 4x4 "kit" while in oz?

regards
Wayne Poulsen
Fremantle

Midwestdrifter
08-12-2018, 03:28 AM
Hey Wayne. We did not end up getting the 4x4 bits in Aus. We just didn't have the time with shipping, and there was some red tape to work out if we wanted to ship the parts back to the states for later use.


In theory, anyone with a Star Diagnostic unit, and a mercedes account (or if you pay a chinese provider who has one) can change SCN coding.

Obviously fitting a NAG1 would be more complicated. My current thoughts, are to fit the normal Sprinter NAG1. Then use a stand-alone NAG1 transmission control unit. This avoids messing with any of the sprinter electronics. Something similar would be possible with the jeep transmission and a manual transfer case. You would need to rig a switch to "trick" the sprinters 4x4 control so it knows when you are in 4x4.

The problem may be that a standalone TCM for the NAG1 is prohibitively expensive. Otherwise you need a TCM, shifter, and relevant wiring from a donor sprinter. It is possible that the factory TCM will just work when connected up to the existing CANbus, and supplied with power. Not terribly likely, so coding various modules etc may be required. In the end, I would not attempt this without a complete donor vehicle. Then I would verify the wiring matches up, and then swap the cluster, ECM, SKREEM etc over to the donor for testing. Fire it up, and see if it drives. If so, You are golden! If not, you will need to work out the kinks. For example, the manual cluster needs a clutch switch input or it won't crank.


I am not 100% sure if the trans type is SCN coded, or if it is a different version of the instrument cluster. Someone with access to mercedes EPC can check to see if manual and auto vans use different part numbers.

All the 4x4s I have seen are 4.16 ratio. I would prefer a 3.73, but not a requirement. If I went to 4.16, I would switch to a taller tire probably.

Any usage of the NAG1 would need some modifications, either to the pan, or the 4x4 input flange. The flange is quite large, so if it was machined a bit smaller, or if the pan was cut and welded, it should clear. If you used the jeep trans (very similar to the NCV3 4x4), you would be making a custom driveshaft, so a changes to the input flange would not pose much extra work.

Midwestdrifter
08-12-2018, 04:59 AM
Doing some more research, it looks like the NV/NP242 transfer case might check all the boxes. It is manual shifting (single cable). It has 2wd, full time 4WD with open center diff, 4Hi (locked center diff), and 4Lo (locked) at 2.7:1. It is used on XJ cherokees and many dodge trucks. It has an indicator cam, which will drive a switch, which could be wired to indicator lights on the dash. It is rated at 1500+lb-ft input torque, so its just as strong as the sprinter factory Tcase. There are numerous output flanges, so it could be modified to work with a single driveshaft type. The NAG1 variant uses a 23 spline input shaft, not sure of the length.

https://www.novak-adapt.com/knowledge/transfer-cases/np242/

trc.rhubarb
08-12-2018, 03:26 PM
I'm really into the idea of this but with the open front an rear diffs, will it make much of an improvement?
Seems like it might be easier to scrap the entire powertrain as it sits and find one from a vehicle that can handle the loads of the sprinter but that offers better components even if still using a 2.7 647 variant from a jeep grand Cherokee or something. Wouldn't it be easier to lift the entire motor/trans/tc/axles/suspension/electronics from a totaled 4d4 vehicle and start over?

It would be cool, no doubt, but if it's not also capable, you just end up with a 2 wheel drive van... 2 open diffs, one front/one rear driving.

It's really a shame that Mercedes didn't see fit to do this from the start. The new vans are just too civilized and 'nice' for an adventure vehicle and unimogs are too slow.

Midwestdrifter
08-12-2018, 04:40 PM
I find it strange how many folks are (seemingly) obsessed with having 2 or three locked diffs.

For those wanting soft or low surface traction the locked diffs are not much help, especially at road speeds. Most folks wanting 4wd need it for winter traction, soft surfaces such as sand or mud, etc. They are not going to be lifting wheels etc.

Two or three locked diffs dramatically increases the risk of driveline damage.

Most of us do not rock crawl.


The rear axle has electronic traction control, which works pretty well. Even with 2WD my van is quite capable with a weight bias on the rear axle.


Have you actually driven the NCV3 sprinter 4x4 with electronic traction control? Most reports are that the system is very capable, both on and off pavement. Even jeep has moved to electronic traction control instead of locking diffs on many of its models. I have seen discussions with jeep development engineers that indicate the high speed traction control system is much more flexible and smooth driving in variable off road conditions that mechanical locking systems. Additionally the lower stresses this approach introduce to the driveline mean that it can be lighter, and less prone to breakage.


That being said locking rear axles are available on T1N 4x4s, and if reasonable I would procure one along with the front subframe.


Unless you can source some European magical parts, fitting running gear from another vehicle is problematic. Look at whitefeather if you need examples. To clear a solid axle in the front the van needs a major lift (way to high for a high roof). Tone rings must be fitted, the steering completely redone etc.

Midwestdrifter
08-12-2018, 04:42 PM
I need some help from a T1N 4x4 owner (Wayne etc).

Can you tell me if the front and rear driveshafts turn the same direction? I am assuming the Factory transfer case is a chain drive type. So if the rear is turning clockwise (looking from the front) so is the front driveshaft?

trc.rhubarb
08-12-2018, 05:09 PM
I find it strange how many folks are (seemingly) obsessed with having 2 or three locked diffs.

For those wanting soft or low surface traction the locked diffs are not much help, especially at road speeds. Most folks wanting 4wd need it for winter traction, soft surfaces such as sand or mud, etc. They are not going to be lifting wheels etc.

Two or three locked diffs dramatically increases the risk of driveline damage.

Most of us do not rock crawl.


The rear axle has electronic traction control, which works pretty well. Even with 2WD my van is quite capable with a weight bias on the rear axle.


Have you actually driven the NCV3 sprinter 4x4 with electronic traction control? Most reports are that the system is very capable, both on and off pavement. Even jeep has moved to electronic traction control instead of locking diffs on many of its models. I have seen discussions with jeep development engineers that indicate the high speed traction control system is much more flexible and smooth driving in variable off road conditions that mechanical locking systems. Additionally the lower stresses this approach introduce to the driveline mean that it can be lighter, and less prone to breakage.


That being said locking rear axles are available on T1N 4x4s, and if reasonable I would procure one along with the front subframe.


Unless you can source some European magical parts, fitting running gear from another vehicle is problematic. Look at whitefeather if you need examples. To clear a solid axle in the front the van needs a major lift (way to high for a high roof). Tone rings must be fitted, the steering completely redone etc.

Lockers might be a bit much but LSD would be ideal. I've lost traction on gravel and I don't find that the minimal traction control I have does much other than limit power output and cause the van to jump a bit as traction is gained/released.

For me, it would be weather related sometimes but more for getting into more remote camping areas, desert sands, etc that are capable by a high clearance 2wd but I find the traction I get in my van is the worst of any vehicle I've ever had.

My first sprinter though, so who knows. What I do see is that with an LSD, I likely wouldn't care about 4wd so much.

My van runs near empty and is for hauling motorcycles and camping out in but not built out as an RV and that may make the difference. First step will be adding better tires to the mix but I don't have high hopes. I'd like true 4x4 with LSD's and a center locking diff. Low range isn't so important for the reasons you mentioned. Occasional trips to the mountains in the winter would be nice but ice isn't a thing at all where I live... sand/silt, rocks, gravel (deep gravel) - those are what I encounter when I travel. Considering I can slip the rear tires on a paved switchback currently, I have little confidence doing the same on an unpaved road. 1000lbs in the back would help, sure...


Anyhow, I'm not trying to poopoo your plans at all; quite the contrary. I want to see it doable at home for $5k in parts and be a solid solution.


I haven't driven a 4x4 ncv3, but I have seen plenty of videos where simple snow stops all forward progress and that turned me off quickly.


Anyhow, I'll be watching with interest. I don't have the skills to design & build a setup myself but as the van ages out, experimenting becomes a potential reality.

I'll check out whitefeather, thanks!

Midwestdrifter
08-12-2018, 11:34 PM
I believe that Quaife made/makes a ATB style LSD that fits the NCV3, maybe the T1N as well?

I have personally seen 4wd vehicles (with and without locking diffs) stuck on flat ground in 4in of hardpack snow. All it takes is a 2" deep divot under each tire, and a bit of spin to make ice.

In my experience a 2WD with snow tires (and chains) will exceed 4WD with summer tires (and also be much safer).


NCV3 4x4 bias most of their torque to to the rear. Running them empty, especially at road pressures will result in poor performance. This is also due to the sway bars and stiff rear springs, as you will easily lift a wheel.

My T1N would lift a rear wheel when entering driveways empty. Not a problem with the conversion weight.


I think a 5,000$ (parts) conversion is a pipe dream. Maybe on a vehicle where used parts were plentiful, and little custom work was required.

I am budgeting about 15K, with 10K being an ideal cost. European sourced front and rear axle $5-8k. Jeep trans/Tcase, $1200 (includes wear parts to transfer sprinter guts). Custom driveshafts, 1500. misc random bits, 2-4k (Tcase shifter, wear parts, fuel tank hoses, low range fix etc).

wayne poulsen
08-13-2018, 04:09 AM
Front and rear driveshafts rotate in SAME direction. Wayne

Midwestdrifter
08-28-2018, 04:40 PM
Greetings once more.

Slowing gathering information on the new approach. I visited a local junkyard today. No NAG1 equipped Jeeps (with 4wd), but I was able to get some measurements from a NP242J t-case on a Cherokee.

https://farm2.staticflickr.com/1897/29389186087_c77cf450f8_c.jpg (https://flic.kr/p/LM2g7X)NP 242 Measurements (https://flic.kr/p/LM2g7X) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1893/29388905057_56e547af60_c.jpg (https://flic.kr/p/LLZPzB)IMG_20180828_091920 (https://flic.kr/p/LLZPzB) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1873/43419056505_d674c2d547_c.jpg (https://flic.kr/p/299N1Nv)IMG_20180828_091603 (https://flic.kr/p/299N1Nv) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1887/30458035108_72a280724e_c.jpg (https://flic.kr/p/NptoGm)IMG_20180828_091600 (https://flic.kr/p/NptoGm) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1849/43419069325_a9dc0d0e20_c.jpg (https://flic.kr/p/299N5Bx)IMG_20180828_092530 (https://flic.kr/p/299N5Bx) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1899/30458050358_c31de19812_c.jpg (https://flic.kr/p/Nptteh)IMG_20180828_092524 (https://flic.kr/p/Nptteh) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1886/43419067065_9455e63bb5_c.jpg (https://flic.kr/p/299N4Wz)IMG_20180828_092520 (https://flic.kr/p/299N4Wz) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1888/43607993634_67f3dcd5d0_c.jpg (https://flic.kr/p/29runed)IMG_20180828_092024 (https://flic.kr/p/29runed) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1862/44324937341_07994fd56a_c.jpg (https://flic.kr/p/2awQTBB)IMG_20180828_091954 (https://flic.kr/p/2awQTBB) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1888/44276889862_172625f987_c.jpg (https://flic.kr/p/2asACLN)IMG_20180828_092003 (https://flic.kr/p/2asACLN) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm2.staticflickr.com/1846/43607981534_a1ce1a9b8a_c.jpg (https://flic.kr/p/29ruiCA)IMG_20180828_091930 (https://flic.kr/p/29ruiCA) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

Midwestdrifter
08-28-2018, 05:53 PM
I believe sourcing a 242 without slip yoke (rear), or using a slip yoke eliminator to switch to a CV style mount would be best. It may be possible to re-use the factory rear half of the driveshaft, and just make a short adapter shaft between the carrier bearing and the Tcase.

Midwestdrifter
08-28-2018, 06:21 PM
Here is the NAG1 with NP242 T case as used on the 2012+ jeep wrangler.

https://www.allpar.com/mopar/transmissions/NAG1-WA580.html

Some useful 242 info, and jeep Tcase references.

http://www.fourwheeler.com/how-to/transmission-drivetrain/154-1201-jp-guide-to-jeep-transfer-cases/

http://www.4x4review.com/jeep-transfer-case-identification-guide/
http://www.novak-adapt.com/knowledge/transfer-cases/np242
https://www.novak-adapt.com/catalog/shifters/sk2x/
http://www.fourwheeler.com/how-to/transmission-drivetrain/1411-1998-jeep-grand-cherokee-zj-np242-hd-sye-transfer-case/

Given that the wranglers are harder to find, and have a higher Tcase clock, I will probably get a NAG1 from a 05+ V6 grand cherokee, then swap the NP247 for a NP242. The NP242J (jeep variant) has a couple versions, including a fairly rare HD version, which is probably not needed for the sprinter.

westyventures
08-28-2018, 06:32 PM
How do you intend to connect this to the Sprinter transmission?

Midwestdrifter
08-28-2018, 06:37 PM
How do you intend to connect this to the Sprinter transmission?

Basically I will be swapping the sprinters trans main case for the jeep main case. So, the guts, valve body, bellhousing, and torque converter from the sprinter will go into the jeep main case. The jeeps main case has the tailshaft and tailshaft housing that will bolt up to a range of NP/NV transfer cases.

Vancompass did the same thing with the ML trans they used on their 4x4 T1N conversion.

westyventures
08-28-2018, 06:47 PM
I didn't realize they used similar/same style cases. My debacle is a little different, since I'm using the factory 5-speed manual trans. I'm also planning to use a 242 transfer case but will have to mount it 'divorced' and fabricate an input shaft + sealed support housing. Unless there is some other 5-speed that is almost identical that will accept the transfer case...

vanski
08-28-2018, 06:58 PM
Lots of US-based 722.6 NAG1s out there - https://en.wikipedia.org/wiki/Mercedes-Benz_5G-Tronic_transmission

Midwestdrifter
08-28-2018, 07:06 PM
I didn't realize they used similar/same style cases. My debacle is a little different, since I'm using the factory 5-speed manual trans. I'm also planning to use a 242 transfer case but will have to mount it 'divorced' and fabricate an input shaft + sealed support housing. Unless there is some other 5-speed that is almost identical that will accept the transfer case...

If obrainger thought it was feasible (for the small T1N 4wd numbers), they would have used a married Tcase, but I doubt the sprinters manual trans has a removable tail housing section.

What not use the factory Tcase? its vacuum actuated, and the low range is only 1.6:1, but its a decent unit. It does not have a center differential though, which can be a deal breaker for some.

If you can source a 5 speed manual trans for a diesel Jeep (with 5 cylinder) those may have the option to bolt on a transfer case? Not sure if that was an option though.

Midwestdrifter
08-28-2018, 07:08 PM
I hopped under the van, and it looks like the Jeep case and trans will fit just fine. Some light trimming on one of the floor supports, but the main structure is all clear. The fuel tank needs to move back about 9", or get replaced with a 4x4 fuel tank.

The factory rear half of the driveshaft could be retained, and a custom front half (about 20" long) could be used from the hanger and slip-joint forward.

westyventures
08-28-2018, 07:24 PM
If obrainger thought it was feasible (for the small T1N 4wd numbers), they would have used a married Tcase, but I doubt the sprinters manual trans has a removable tail housing section.

What not use the factory Tcase? its vacuum actuated, and the low range is only 1.6:1, but its a decent unit. It does not have a center differential though, which can be a deal breaker for some.

If you can source a 5 speed manual trans for a diesel Jeep (with 5 cylinder) those may have the option to bolt on a transfer case? Not sure if that was an option though.


Impossible to find; I want a lower ration low-range (33" tires); full-time 4WD option. The other issue with 'other' transmissions is that I want to retain the factory dash-mounted cable shifter setup that I already have.

AdrianD
08-29-2018, 09:52 PM
Basically I will be swapping the sprinters trans main case for the jeep main case. So, the guts, valve body, bellhousing, and torque converter from the sprinter will go into the jeep main case. The jeeps main case has the tailshaft and tailshaft housing that will bolt up to a range of NP/NV transfer cases.

Vancompass did the same thing with the ML trans they used on their 4x4 T1N conversion.

Good, good.

Get an NP242 off an XJ, you don't want the stupid cv style joints that are on the Grand Cherokees. At least not at the t-case on the front output.
The Sprinter is long, no need for a slip yoke eliminator.

AdrianD
08-29-2018, 09:54 PM
Impossible to find; I want a lower ration low-range (33" tires); full-time 4WD option. The other issue with 'other' transmissions is that I want to retain the factory dash-mounted cable shifter setup that I already have.

Samurai's have divorced transfer cases and can be upgraded to real low low gears.

Midwestdrifter
08-29-2018, 10:10 PM
Good, good.

Get an NP242 off an XJ, you don't want the stupid cv style joints that are on the Grand Cherokees. At least not at the t-case on the front output.
The Sprinter is long, no need for a slip yoke eliminator.

I did notice that the XJs used a typical yoke.

So, whats the problem with the CV joints on the front output? The rear slip yoke is pretty long on the Cherokees, I was a bit concerned about the loading on the Tcase, is this not an issue?

Assuming my angles allow, the front driveshaft will likely be standard UJs, ideally with spicer replaceable cores. If the price is right, I will go all new for the rear, but with the length I will likely still need a single carrier near the T case, which may complicate things. Given that there will be a carrier, retaining the factory rear slipyoke shouldn't be a problem.

Are the aftermarket style jeep UJ/driveshaft bits sturdy enough for a moderately used T1N (8500lbs)?

I am not sure if I will need a CV style front driveshaft, the sprinters input on the front diff is pretty far back (about 3/4 the way forward on the trans pan).

owner
08-30-2018, 09:50 AM
Unless there is some other 5-speed that is almost identical that will accept the transfer case...
The W163 ML270 was available with a 6 speed manual trans option. That is OM612 on one end, and a married Tcase on the other. I think they are pretty rare though, and the Tcase is open diff. Also the engine was derated from 400Nm for the 722.6 down to 370Nm for the manual, so presumably the trans isn't very strong. It has a super low first gear, and the already super low ML Tcase low range so thats probably the only good thing. Oh and you would need to import from Europe.

AdrianD
08-31-2018, 10:05 AM
I did notice that the XJs used a typical yoke.

So, whats the problem with the CV joints on the front output? The rear slip yoke is pretty long on the Cherokees, I was a bit concerned about the loading on the Tcase, is this not an issue?

Assuming my angles allow, the front driveshaft will likely be standard UJs, ideally with spicer replaceable cores. If the price is right, I will go all new for the rear, but with the length I will likely still need a single carrier near the T case, which may complicate things. Given that there will be a carrier, retaining the factory rear slipyoke shouldn't be a problem.

Are the aftermarket style jeep UJ/driveshaft bits sturdy enough for a moderately used T1N (8500lbs)?

I am not sure if I will need a CV style front driveshaft, the sprinters input on the front diff is pretty far back (about 3/4 the way forward on the trans pan).

The CV joints used in the WJ are usually crappy. Even worse for aftermarket options. I had to remove my front driveshaft in the middle of the night coming back from a roadtrip. Good thing it only made noise twice at highway speeds and when it finally let go it was under 20 mph. Now I have a double-cardan at the transfer case end and I can't complain about smootheness compared to the original driveshaft.

I'd just use a stock Jeep setup with custom lengths. IIRC a custom front driveshaft with 1310 Spicer u-joints (double cardan at the transfer case) is around $300. The rear should be cheaper since it's single cardan at both ends. So you'd have to worry only about aligning the rear.
You could go with 1330 series u-joints if you are worried about strength.

Regarding 5-speeds and older manual gearbox options, keep in mind that the G-class has a divorced transfer case. I think the married transfer cases appeared only after the ML.

Midwestdrifter
09-03-2018, 07:03 PM
Another update.

Visited a local junkyard. Lots of 242 tcases, 70$ all day long. I picked one up to play with.

https://farm2.staticflickr.com/1881/44451403281_ec20e2be6a_c.jpg (https://flic.kr/p/2aJ24wR)IMG_20180903_095638 (https://flic.kr/p/2aJ24wR) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

Some things learned. Grand Cherokees with the V6 and NAG1 DO NOT use the 242, they use the NV140 or 245. These Tcases use a different bolt pattern, and thus the tailshaft adapter is different.

Grand cherokees compatible with the 242 use the 247 Tcase. They are the 02-04 diesel. THe 2012+ wrangler comes with the 241 (possibly 242 on some models) and NAG1. These models will have the correct trans and tailshaft to accept the 242, and sprinter specific bits.

Here is the incorrect 245/140 adapter.
https://farm2.staticflickr.com/1896/30582070408_099bd786aa_c.jpg (https://flic.kr/p/NAr751)IMG_20180903_102428 (https://flic.kr/p/NAr751) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

Here is the correct bolt pattern on a 242/247 etc.
https://farm2.staticflickr.com/1883/43734149844_d47f354183_c.jpg (https://flic.kr/p/29CCX5h)IMG_20180903_110413 (https://flic.kr/p/29CCX5h) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

The 242 had internal shift detents, and a analog position sensor/switch. So it is really ideal for this application. Shift force is quite low, and just about any cable shifter can be rigged up to work. If needed there are heavy duty versions of the 242 with wider chain and larger outputs that were used on the Hummer and possible dodge truck applications.


T1N 4x4s are not very common, between the age, poor paint, and low production numbers, they don't come up for sale often, even in germany. The good news is that they are not very sought after either, so prices are not crazy

I have reached out to a few folks to see if anyone has a lead on parts or complete vehicles that are available.


If anyone else is interested in splitting shipping for some T1N 4x4 bits, let me know.

AdrianD
09-04-2018, 07:38 AM
I think I can ship you the correct NAG1 extension housing. Should be cheap to buy, I just have to find it. My spare transmission doesn't have it.

This is the adapter you need:
https://i.imgur.com/27INFMJ.jpg
https://i.imgur.com/SirRZDO.jpg

Midwestdrifter
09-04-2018, 01:10 PM
I think I can ship you the correct NAG1 extension housing. Should be cheap to buy, I just have to find it. My spare transmission doesn't have it.



Thanks! I am interested for sure. The other concern is the tcase input shaft needs to match the tail shaft, so I need a matching set I think?

AdrianD
09-04-2018, 01:57 PM
Yes, you also need the output adapter which does on the WG (European designation WJ) NAG1. It's different from the WK/JK.
I'll ask around and see if somebody is willing to separate both parts from the transmission.

Midwestdrifter
09-04-2018, 02:05 PM
Yes, you also need the output adapter which does on the WG (European designation WJ) NAG1. It's different from the WK/JK.
I'll ask around and see if somebody is willing to separate both parts from the transmission.

Great! Let me know what you find. There is no rush though. I am sure we can work out pricing/shipping. If a trade is desired, I can pull some USA only parts from a yard to send over.

There are several good jeep NAG1 transmissions in my local yard, so I can grab a main case to work with cheap/easy.

I need to get a copy of the Jeep illustrated parts catalog as well. This is the beauty of the Jeep parts approach, they are common enough that replacement wear bits are cheap.

AdrianD
09-04-2018, 08:31 PM
Tell me your email address and I will upload the whole WG/WJ documentation I have.

AdrianD
09-05-2018, 08:24 AM
I've called a good friend which did the JK OM612 swap. The WK output shaft is also different.
You'd need a JK or WG output shaft, intermediate shaft and adapter housing. Which he can supply :)

Next big issues:
Front axle. What is the width and gear ratio of the rear axle? Axle widths for Jeeps (wheel mounting surface to wheel mounting surface): XJ/TJ/ZJ - ~60", WJ - 63.5", JK - 66.5"
Low-range. How are you going to trick the TCM?

Midwestdrifter
09-05-2018, 01:44 PM
I've called a good friend which did the JK OM612 swap. The WK output shaft is also different.
You'd need a JK or WG output shaft, intermediate shaft and adapter housing. Which he can supply :)

Next big issues:
Front axle. What is the width and gear ratio of the rear axle? Axle widths for Jeeps (wheel mounting surface to wheel mounting surface): XJ/TJ/ZJ - ~60", WJ - 63.5", JK - 66.5"
Low-range. How are you going to trick the TCM?

Great! Jeep guys certainly are a friendly bunch.


For the front axle I am planning on using the Sprinter Factory 4x4 front subframe. So it will have a 4.16 ratio with independent Strut setup (basically the same as the 2wd).


Low range is going to take some time. I have outlined an approach that will use an arduino to intercept CAN frames from the cluster, and modify the driveshaft speed when in low range. There are some boxes from german conversion companies that do this, but they are very hard to find.

AdrianD
09-05-2018, 03:47 PM
On what side is the diff on the factory subframe? I hope it's on the left...

Midwestdrifter
09-05-2018, 03:57 PM
On what side is the diff on the factory subframe? I hope it's on the left...

Yep, left! Right side Drive transfer cases aren't all that common. Which would've made it quite difficult.

Midwestdrifter
10-11-2018, 11:24 PM
Just for kicks here is the Mopar parts list for the transfer case adapter and shaft. This is what is used in the wrangler and will connect the NP 241 or 242 transfer case to the jeep NAG1 transmission. looks like all parts are readily available and reasonably priced.

https://www.moparpartsgiant.com/parts-list/2012-jeep-wrangler/automatic-transmission-case-adapter.html

ocbones
10-14-2018, 04:24 AM
:popcorn:

Midwestdrifter
10-15-2018, 04:02 PM
I am still trying to track down a factory front subframe. I have had minimal success. Older vehicles don't hang around long in western europe, so i might need to look farther east.


I am also considering if a NCV3 front axle and subframe can be adapter to the T1N. Obviously there will be a fair bit of fabrication. The NCV3 has a 3" wider track, and the frame rails are also about 3" wider. An adapter plate would be needed to mount to the T1N frame rails (or fabrication matcing bolt holes in the NCV3 subframe).

It is likely possible to section the NCV3 subframe so it is 3" narrower. Then use a custom driveshaft on one side? I need to find a NCV3 4x4 that I can measure (likely hard since I am in Souther missouri currently!).


The NCV3 was available with 4.182 gear ratio (3500 series?). This is a close enough match to the 4.16 T1N ratio.

The wheel speed sensors may need modified. Anyone know how many teeth are on the NCV3?



The other issue is that the NCV3 uses a wheel with offset of 63mm, while the T1N uses 54mm. So the NCV3 mounting flange is 9mm father outboard from the tire centerline, so that extra distance would need to be considered if track was to remain the same.

Of course I could just accept a wider track, there is plenty of room for it.





If anyone knows a wrecker/salvage with NCV3 4x4s let me know!



Here is my ideal scenario for the NCV3 route.

Obtain 4.18 ratio NCV3 4x4 front subframe/axle etc. Switch my van to a 4.16 T1N rear R&P.

Use adapter plates to bolt a lightly modified NCV3 subfram onto the T1N. Modify engine mounts as needed for the 5cyl.

Use adapters to mount the T1N or NCV3 struts. The steering should be similar.

Use the previously discussed NV242 married Tcase.

Explore South America. :rad:

vanski
10-15-2018, 04:41 PM
I might be able to help on the NCV3 route... if the set is still available. wondering if you could utilize the ncv3 tcase instead of the nv242. He had that...

Midwestdrifter
10-15-2018, 04:47 PM
I might be able to help on the NCV3 route... if the set is still available. wondering if you could utilize the ncv3 tcase instead of the nv242. He had that...

The NCV3 Tcase could be used (along with the trans main case if reasonably priced). The issue with the NCV3 case is that it is electronically shifted, so a control scheme would need to be rigged. I think its a pretty simple control scheme though. I don't see a huge advantage to the NCV3 Tcase, as I would likely need custom driveshafts regardless, unless the engine and axle positions are extremely cose to the NCV3 (not likely).

The NCV3 Tcase has no locked center diff, and uses a torque split. Low range is an option though.


I would be interested if the diff is 4.18 ratio. :thumbup: If he can provide a VIN, I can loop up the axle ratio.

Lots of questions to answer. I really need an hour underneath an NCV3 4x4 to take measurements.

vanski
10-15-2018, 04:57 PM
i wouldn't be able to get the vin on the wrecked unit until Friday, most likely Saturday..

i also have a 4x4 landing on my driveway today and could take some rough measurements. lots of work to do on this thing though so I could really only spare an hour or so.

Midwestdrifter
10-15-2018, 05:04 PM
i wouldn't be able to get the vin on the wrecked unit until Friday, most likely Saturday..

i also have a 4x4 landing on my driveway today and could take some rough measurements. lots of work to do on this thing though so I could really only spare an hour or so.

Yeah. No worries, and there is zero rush.


The detailed measurements I want from a 4x4 would be a pain to explain, and would probably take you way to long. So don't worry about it. I just need to find an owner in my neck of the woods!

I was hunting on Copart, and there was a wrecked NCV3 4x4. Just one of course. I will set up some alerts on there so I get notified if any come up.

Midwestdrifter
10-19-2018, 08:33 PM
Okay, so after examining photos and looking at some rough measurements, I believe a NCV3 4x4 front subframe could be made to work. An adapter plate would need to be made for left and right frame rails (the T1N is 3" narrower overall). This also means a larger track in the front (3" wider). Switching to the NCV3 6 bolt wheels with adapters on the rear would allow a single spare, and match the track width front-rear.

An adapter would need to be fabricated to attach the T1N strut. The NCV3 uses a single flange strut mounting about 90 degrees off from the T1N, so a Tee shaped adapter plate(s) should do the trick. The OM612/647 engine mount towers are different, so it would be easiest to just cut them off a donor subframe, and weld to the NCV3 subframe.

If necessary a new tone ring can be cut (not sure if the NCV3 uses the same number of windows).

The good news is that all this is pretty straight forward. In a perfect world it could be a bolt-on kit, but thats not likely.

My only major concern at this point is steering ratio (ESP vans), and interference with the racks input shaft. The shaft is fairly close to the frame rail, so it may be a tight fit. Worst case a T1N rack could be used, and tire rod extension machined.

westyventures
10-19-2018, 09:23 PM
Call me confused, but I haven't been following for awhile - I thought you had access to everything in Oz or somewhere? The factory parts bolt up so well, so why would you want to use the front from a later model? I've found a guy in Europe who parts out 4x4 Sprinters and claims to have everything needed, including a full Iglhaut setup for T1N if desired. I'm still plodding along on my own T1N project with what little time I've had to spare, everything has been media blasted and coated with black epoxy. Assembly is imminent and it looks fairly easy to bolt everything in other than the transfer case, which I'm still thinking about what option to go with.

Midwestdrifter
10-19-2018, 09:27 PM
Call me confused, but I haven't been following for awhile - I thought you had access to everything in Oz or somewhere? The factory parts bolt up so well, so why would you want to use the front from a later model? I've found a guy in Europe who parts out 4x4 Sprinters and claims to have everything needed, including a full Iglhaut setup for T1N if desired. I'm still plodding along on my own T1N project with what little time I've had to spare, everything has been media blasted and coated with black epoxy. Assembly is imminent and it looks fairly easy to bolt everything in other than the transfer case, which I'm still thinking about what option to go with.

I ran into a roadblock getting parts from Aus. I was stupid and didn't jump on the chance while I was there.

I have had limited success tracking down T1N 4x4 bits in europe. If you have a source, please share it! PM me if you want to keep the info off the public thread.

I would obviously prefer T1N bolt on parts, but if I can't source any, the NCV3 parts are a backup plan.

AdrianD
10-22-2018, 08:58 AM
I am still trying to track down a factory front subframe. I have had minimal success. Older vehicles don't hang around long in western europe, so i might need to look farther east.


They are rare here too as far as I know but I can check.
Still delayed with the existing parts as I'm on a work trip and my buddy was on a "work" trip with some FCA management from Europe...riding around Montenegro in JK Wranglers :D

owner
10-25-2018, 10:58 AM
Hows this for an idea out of left field... :popcorn:

Instead of running a sprinter (or other) TCase, have you considered adding an EV electric motor to drive the front diff? You are already carrying a battery bank after all.

So have the stock Sprinter front diff with the stock propshaft bringing it back to where the stock Tcase would live. Then mount say a 30kW EV motor there instead of a TCase. A 30kW motor would weigh roughly the same as a TCase, less if using an AC motor. I believe this is called a "road coupled parallel hybrid". I said 30kW because thats about how much power is needed to drive a sprinter at 60mph on the flat. But you could choose any motor that fits.

The range of rpm through the stock 4.1 diff would be pretty much perfect 0-3000rpm motor rpm would be 0-60mph. You could even keep your stock 3.7 rear diff. AC motors around 30kW output are delivering a flat 110Nm of torque from 0 right up to 3000rpm. And 30kW DC motors are delivering 3x that torque.

Since you already have a house battery bank, you are eliminating one of the main drawbacks of parallel hybrid, in that you would be carrying extra weight in batteries. In the case of a sprinter campervan, you are already carrying that weight, so its all pure profit. The other drawback is losses in the "other" drivetrain, in this case the front diff. But you will be going 4x4 anyway so the losses are also already there - win win again.

You can configure these EV controllers pretty easily, there are even controllers that use your OBD port to decide when and how much hybrid power to deliver http://www.go-ev.com/EMIS.html. Worst case you could even just mount a small "joystick" to the top of your shifter to control it manually. You could even have it tied into the throttle pot, and with adjustable aggressiveness for when you want serious 4x4 mode.

You could program it to be like a Prius.. Lots of EV power on takeoff and during accel, then switching over to 100% ICE when approaching highway speeds, or when on a lower constant cruising speed. And have it kick in under high loads regardless. This could be easily knocked up with an arduino, all the motor controller needs to see is a 0-5V "throttle" input.

You could even do my Cam signal mod (which I've not actually tried yet) to switch the ICE in/out of silent limp mode so that it uses even less fuel and short-shifts the trans when using EV power.

So given this 4x4 camper application, the Advantages are:

More power! with zero extra stress on the stock components.
Less stress on the ICE drivetrain.
Better fuel economy via regenerative braking.
Less brake wear.
Better braking down long hills.
Redundancy - can run exclusively on either drivetrain in emergencies.
Keeps the 3.7 rear diff for better freeway driving.


Disadvantages:
???

wayne poulsen
10-26-2018, 08:51 AM
Very lateral Owner
Whilst day dreaming the perfect...whatever
I wondered about an Emotor third axle as a 6x6 solution?
You are clearly able to think it further thru than me.
How bout a 6x6 using mitsi PHEV axles?
Wayne
But I would be content with an auto 4x4 tin, hence i keep following this thread.

calbiker
10-26-2018, 05:34 PM
I think electric front wheel drive is an excellent idea. It would require a larger Lithium battery which could be charged from the alternator. The mechanical design looks much simpler than what's discussed earlier. Don't know how the front and rear wheels are synchronized.

Hows this for an idea out of left field... :popcorn:

owner
11-01-2018, 08:47 AM
I don't think this will fit the sprinter.
https://www.brusa.biz/fileadmin/template/Produkte/Antrieb/BRUSA_B_DTSO1.jpg

The final drive part with the diff output flanges is less than 290mm high, but I don't think the motor will fit where it would have to be. You could probably use a smaller motor though. Its made by Oberanger (just like the Sprinter front diff is). 9.59:1 ratio.

https://www.brusa.biz/en/products/drive/drivetrain-unit/dtso1-096.html

Its basically the same setup as I was proposing (using the sprinter front diff). But the motor would be on the end of the stock propshaft where there is a lot more room.

But this should probably be in its own thread if anyone was to pursue it further, I was just throwing the idea out there as an alternative to poncing about with transfer cases.

Midwestdrifter
11-01-2018, 02:44 PM
They are rare here too as far as I know but I can check.
Still delayed with the existing parts as I'm on a work trip and my buddy was on a "work" trip with some FCA management from Europe...riding around Montenegro in JK Wranglers :D

No worries, whenever you get a chance!


Hows this for an idea out of left field... :popcorn:

Instead of running a sprinter (or other) TCase, have you considered adding an EV electric motor to drive the front diff? You are already carrying a battery bank after all.

....




So, I have actually built and worked on a few custom electric conversions. What you are proposing would involve lots of fabrication/machining of custom one off precision parts. Not for the faint of heart. A custom motor cradle, and compact high output motor.

Then plenty of wiring, expensive motor controller, and finding a way to integrate the motor control with the existing throttle.

Then I need an sizable lithium pack, somewhere near 10kwhr. Then I would probably need to upgrade the alternator unless I go with regen braking.

That would cost 3x what I am looking at spending now, and I would still need a 4x4 front subframe.


Pulling a bunch of existing parts, and re-assembling them into a sprinter trans/tcase seems a lot cheaper and simpler. Almost all the engineering is already done.


I am putting together a parts list for a friend of a friend to translate and send to some German folks who part out 4x4 vans. Hoping to get some traction on parts before the end of the year (no pun intended).

Midwestdrifter
11-04-2018, 08:36 PM
Quick update:

I have plans to grab a jeep NAG1 in a few weeks. I still have not had any luck with finding a NAG1 tailshaft adapter for the NP242 in the USA (other than new from the dealer $$) Folks either trash them, or want to sell the entire trans from a late model wrangler.


A friend and I are in early contact with a guy in Germany who regularly parts 4x4 vans. It looks like 4.375 is the more common gear ratio. This is probably tolerable, but its 17% higher than my current 3.73, and 10% higher with 245/75R16 tires.

Below are some photos from Westyventures of his conversion in process.

westyventures
11-04-2018, 08:39 PM
That is lower ratio, not higher.

Midwestdrifter
11-04-2018, 08:40 PM
That is lower ratio, not higher.

Yeah, brain fart. Higher RPM, lower ratio.

What gear ratio are your axles?

westyventures
11-04-2018, 08:57 PM
I'm not sure, it's been a few years but do remember them being lower than the stock 416 2WD axles I have.

Midwestdrifter
11-04-2018, 09:29 PM
I'm not sure, it's been a few years but do remember them being lower than the stock 416 2WD axles I have.

If you happen to have a vin from the donor, I would be curious to look up its build sheet.

owner
11-05-2018, 06:27 AM
That would cost 3x what I am looking at spending now, and I would still need a 4x4 front subframe.

So just to close my threadjack off... If cost wasn't an issue, do you think it could be a good solution? I can't really see any downside to doing it on this application, and plenty of upside.

Just to be clear the only major fabrication I'm proposing would be a motor mount and the mating interface for the motor to front propshaft. All the rest would be stock T1N 4x4 parts.

Also I would be doing the hybrid throttle interface myself, since its part of my day job anyway, so that would basically be "free", and would be good experience which I can use to further my career.

So I'd be looking at a motor with controller for around $4k, and I can get 10kWh of LFP for around $4k. (BTW have you seen the sizes of some of the LFP banks folks on here are putting into their RV sprinters lol). Plus the factory 4x4 parts which I'm not factoring in since they would be needed either way (sans tcase).

BTW all Erics 4x4 T1Ns have 4.111 diffs "AC2" code. I didn't know 4.375 was an option on the 4x4, thats going to be quite high revving for highway driving with the auto trans. Would be good for EV use though :shifty:

Midwestdrifter
11-05-2018, 04:53 PM
So just to close my threadjack off... If cost wasn't an issue, do you think it could be a good solution? I can't really see any downside to doing it on this application, and plenty of upside.

Just to be clear the only major fabrication I'm proposing would be a motor mount and the mating interface for the motor to front propshaft. All the rest would be stock T1N 4x4 parts.

Also I would be doing the hybrid throttle interface myself, since its part of my day job anyway, so that would basically be "free", and would be good experience which I can use to further my career.

So I'd be looking at a motor with controller for around $4k, and I can get 10kWh of LFP for around $4k. (BTW have you seen the sizes of some of the LFP banks folks on here are putting into their RV sprinters lol). Plus the factory 4x4 parts which I'm not factoring in since they would be needed either way (sans tcase).

BTW all Erics 4x4 T1Ns have 4.111 diffs "AC2" code. I didn't know 4.375 was an option on the 4x4, thats going to be quite high revving for highway driving with the auto trans. Would be good for EV use though :shifty:

Sure, if you were looking for a project and had sources for the parts. I don't see any impossible issues. The biggest challenge is going to be finding space for the electric motor. Direct drive would be ideal, but it would need to be a very compact motor to fit alongside the trans.

Midwestdrifter
11-05-2018, 05:10 PM
So the ratios I am finding are 4.11 and 4.375. The manual 5 speed has a 0.78 5th, the NAG1 has a 0.83.

So with 245/75R16 tires at 2500rpm:


3.732, 73mph
4.111, 66mph
4.375, 62mph

Switching to 235/85R16 tires:

3.732, 76mph
4.111, 69mph
4.375, 65mph

Our van is heavy, so 3.725 is marginal in hilly country with taller than stock tires. 4.11 would be good. 4.375 is to low by about 5% ideally. Switching to a taller tire helps though. With a 32" tall tire, the 4.375 is tolerable.

Here is a handy calculator. It has tire sizes, and even has an NAG1 gear ratio selection.
http://www.grimmjeeper.com/gears.html

owner
11-05-2018, 11:40 PM
The other thing to consider is the noise and drag from the front diff. This is probably going to be worse the lower the ratio.

Eric has a theory that at high speeds, the oil in the front diff migrates to one side. This was during a high speed run in the NT. I think he said 150kph. It started off all fine, then after a short while the front diff gradually started making a lot more noise. So he had to back off.

wayne poulsen
11-06-2018, 02:22 AM
150kph? 94 mph, chasin the ton!
Eric the revhead!
Wayne
fremantle

Midwestdrifter
11-06-2018, 02:29 AM
Yeah, when crossing from WA into NT You hit that 130kph zone. Its tempting, for a second. I opened her up. Not much happened really, gradually climbed from 100 to 140kph. Like all USA sprinters, mine maxes out at 82mph or so, with the larger tires I can hit a bit more. Its scary to think that its some 20 seconds of WOT to get there. All the energy stored as speed. The thought of hitting a roo, or just the dips in the road had me slowing down quick. That and the cost of diesel...

I will never be driving that fast for more than a few minutes at a time anyways. My preferred cruising speed is about 105kph. I will sometimes push 110 to keep up with traffic. Though in the western USA, the semi trucks are often doing 80mph (130kph). Which is scary enough.

With the 5 speed manual, 4.11 and 235/85R16 tires, you would be running 3200RPM at that speed. A bit high, but nothing the OM612 cant handle.

owner
11-06-2018, 08:27 AM
I did an indicated ton in mine when I first picked her up. I'd never really driven a sprinter before, and I'd never overtaken a road train on the open road before either. So I gave her a decent run-up and then just floored it as I pulled out. The van just flew past that beast like it was standing still, I looked down and saw 160kph/4000rpm at which point I lifted off for fear of being thrown in jail. Its top end performance certainly caught me by surprise. Van was bouncing around all over the place and showed no signs of reaching any kind of limiter. This was on 15" wheels, and an indicated 160kph is probably more like 145kph lol. The ambos all have the rev limiter set to 4400rpm and the speed limiter is set to max which is 161kph (which I think means no limiter).

calbiker
11-06-2018, 11:49 PM
That's a 150 kW motor. That's more than the T1N outputs! What do you need up front, perhaps 20 kW?



https://www.brusa.biz/en/products/drive/drivetrain-unit/dtso1-096.html

Midwestdrifter
11-06-2018, 11:55 PM
Instead of power, I would be interested in the the stall torque the motor generates at low RPM. A ratio in the 5:1 range for the front diff would be better. It just depends on your usage case. For me I need the front drive when I am going slow (or stopped). While those with AWD type needs would want signficant power at medium to high speeds, so climbing a hill at 30mph for example.

Midwestdrifter
11-07-2018, 12:29 AM
So the NP242 Tcase is rated at 1486lb-ft of input torque.

The NAG1 first gear is 3.59:1 and the engine peak torque is 243lb-ft. The TCs multiplication factor is about 2.

So estimated Tcase input torque is 243 x 3.59 x 2 = 1745 lb-ft. This only at or near stall.


So to avoid unnecessary wear on the Tcase, one should avoid full throttle in first gear. 90% should be okay. I doubt the Tcase will explode if this is exceeded though.

This weak point (if it can be called that) on the NP242 is the torque biasing differential. In 2HI and 4 locked/low the differential is not engaged. So when in AWD mode, keep your foot out of it in 1st gear!

owner
11-07-2018, 07:37 AM
That's a 150 kW motor. That's more than the T1N outputs! What do you need up front, perhaps 20 kW?

Instead of power, I would be interested in the the stall torque the motor generates at low RPM. A ratio in the 5:1 range for the front diff would be better. It just depends on your usage case. For me I need the front drive when I am going slow (or stopped). While those with AWD type needs would want signficant power at medium to high speeds, so climbing a hill at 30mph for example.
I have replied to these posts in a shiny new thread here https://sprinter-source.com/forum/showthread.php?t=70798.

AdrianD
11-08-2018, 03:12 PM
So the NP242 Tcase is rated at 1486lb-ft of input torque.

The NAG1 first gear is 3.59:1 and the engine peak torque is 243lb-ft. The TCs multiplication factor is about 2.

So estimated Tcase input torque is 243 x 3.59 x 2 = 1745 lb-ft. This only at or near stall.


So to avoid unnecessary wear on the Tcase, one should avoid full throttle in first gear. 90% should be okay. I doubt the Tcase will explode if this is exceeded though.

This weak point (if it can be called that) on the NP242 is the torque biasing differential. In 2HI and 4 locked/low the differential is not engaged. So when in AWD mode, keep your foot out of it in 1st gear!

I suspect the NP247 which I have is rated similarly and they last for a long time.

Not my Jeep or my picture, I've only had mine up to 160km/h:
https://i.imgur.com/dDxIW1j.jpg

Midwestdrifter
11-08-2018, 07:44 PM
Just for completeness sake. Apparently oberaigner made a T1N 4x4 with 5 speed manual and intergral transfer case. Note the dual CV front driveshaft.

Midwestdrifter
12-21-2018, 08:11 PM
Well my latest attempt at getting parts from Europe seems to have fallen through. Still looking though.


Looking for more readily available parts donor wise, I took a look at a GMT-800 (suburban, silverado, tahoe 99-06) front ends. These vehicles basically check all the boxes except that they are double A arm, not strut. Some photos are attached.


Pros:
Both 4.11 and 3.73 gear ratios from the factory
Similar GAWR to sprinter
Torsion springs compatible with non-load bearing sprinter struts.
torsion springs allow easy ride height adjustment
Similar sized brakes
Cheap and plentiful parts
Strong differential and driveshafts
Steering and swaybar located properly
Total travel is slightly higher than stock sprinter
Factory wheels use a smaller offset than sprinter, so a wheel adapter could be fitted without changing track width significantly.
Track widths match
Sprinters steering rack is retained (might need to extend steering shaft)


Cons:
new subframe must be fabricated/designed
Knuckle/upgright must have a bracket welded on for sprinter strut
Tone rings must be replaced (probably), as tooth count likely varies

I am in the early stages of this approach, but here is my plan.

Measure both vehicles and make rough models in CAD. If parts are compatible dimensionally, I will make a wooden rough mockup and attach the GM parts. if everything clears, I will design a metal subframe. I would make 90% of it from laser cut steel plate with interlocking tabs. So assembly and welding/fabrication will be simple. Then the uprights will get a laser cut steel bracket welded on for the sprinters strut. In addition a transverse bracket will need made to mount the other end of the torsion spring. This could likely be combined with the new trans support which will be needed for the T/case

I anticipate using the following parts from the GM donor
Complete diff and half-shafts
Kuckles, brakes, bearings, etc
low A arm and Torsion spring

Kept from Sprinter
Steering rack
Inner tie rods (outers will need an adapter for the GM end joints)

It seems like a lot of work. Thankfully once the measuring and design work is done, I can just send some drawings to my local machine shop, and cut out 100 hours of work. I have done suspension design previously for a race car, so I am familiar with the modeling needs and design constraints. Within limits I can also set the suspension parameters to improve ride and steering. With a bit of design work, I would bet the whole kit could be adapted to the NCV3.

Some rough parts prices (aftermarket)
Diff assembly $1,100
axles $100
Wheel/hub assembly, $35

Midwestdrifter
12-28-2018, 03:29 PM
Another brief update.

I am digging into GMT-800 front suspensions, and found some useful information.

There are two major variants, and 2 sub variants of the GMT-800 front end (not counting 3500 weight class). The major variants are 1500 and 2500 weight classes. The sub variants are truck and SUV. The biggest difference between truck and SUV seems to be track widths, and overall travel.

The 2500 uses a heavier wheel bearing and strong control arms. It also uses a 8x165.1 wheel pattern with 116.6mm center bores. The wheel bearing is much heavier, and the hub mount uses 4 bolts (Vs 3). Photo comparison attached. Best I can tell on some vehicles it also has a wider track width. Around 36-50mm wider possibly? I need to measure a couple of vehicles to see whats up. It doesn't seem consistent between truck and SUVs though. The numbers I am seeing on the web are 65-68". The T1N is 65", and I don't want to go much wider than that. With the T1Ns high offset wheels, There should be enough room for wheel adapters without changing the track width much, assuming I start with a 65" vehicle. There are different lengths of CV axles, so I have some wiggle room of about 18mm per side to adjust the A arm positions if needed, but I would like to avoid that if possible.

The 2500s come with a larger front diff. The lighter duty front diff is 8.25", the heavy duty one is 9.25" R&P. There are some locker and limited slip diffs available for the 9" front diff as well.

The 2500 (and some 1500HD) come with larger brakes on the front. They are about 20mm larger diameter, and nearly double the thickness. (Still with a 16" wheel though). This is significantly larger than the T1N front brakes, both in diameter and overall weight.

Given that the sprinter has a fairly heavy front end, I think I will pursue the 2500 series parts. They are not as common, but I think they will provide much better service in a heavy van application.

The GMT-900 brakes will bolt on to the GMT-800 hubs/uprights with no mods. That allows a 13" rotor! Very nice really. However they require a 17" wheel, which is a whole different rabbit hole.
http://z71tahoe-suburban.com/iboard/index.php?showtopic=28846&st=20

az7000'
12-28-2018, 04:47 PM
I'm a proud owner of a 2003 Chevy Avalanche 2500. Has an 8.1l gas motor and the 4L85e trans, 13mpg if I'm lucky.

My insight is that at 160k miles I have replaced both of the front hubs, they come as a complete unit with the abs sensor, abs faults, replace the entire hub. I just put on a new box, pitman and idler arms also. for myself and others who are light on the wheel it drives fine but if you are "steering" the truck all of the time it definitely feels loose, a friend drove us on a leg and after 120 miles my 5yo puked and I was a bit motion sick from him sawing on the wheel, relieved him of his duties. I think my truck weighs about 6600# with the big block sitting right over the front end. I'm good with the loosish feel but understand it is a 16 yo truck, not a modern unibody vehicle with weaker stamped parts. With the high cg on our motorhome I would question the set up, with a converted van I think I would be good with it.

LMK if I can measure anything for ya or shoot some pictures.

Midwestdrifter
12-28-2018, 05:01 PM
...

LMK if I can measure anything for ya or shoot some pictures.

That roughly my experience on several previous GMT-800 vehicles. At 220k miles both front hubs on the 1500 suburban were worn out, and the steering joints at the pitman and idler arms were toast.

Thanks for the offer! Any photos you could provide would be great. A-arms, diff and mounting, brakes, sway bar, etc. Is this a 4x4 or 2wd? I will send you a PM with my email address.

If you could measure the track width on the front (center to center) that would be ideal. Do you know what offset of wheels you have? I can probably look it up if you don't.

If possible could you measure the distance between the centers of the front lower A-arm mounting bolts?
Thanks!

It has been pretty cold here the last couple days, so I have not hit up the local junkyards to see if any 2500 trucks/SUVs are available.

Midwestdrifter
12-28-2018, 06:49 PM
Some more info on the 9.25" GM front differential.

https://www.dieselworldmag.com/gm/ultimate-axle-build-building-a-super-strong-9-25-aam-front-axle-for-your-gm-or-dodge-part-2/#

Most are equipped with a CAD (center axle disconnect) which saves some fuel economy, and can be configured to allow 2WD low range operation with the 242 Tcase. Pretty useful for low speed driving on steep hills where 4WD isn't needed.

Several locking diffs are available (not really needed in my opinion). Helical Limited slip diffs are also an option, and may be worth the cost. The helical torque biasing diffs tend to play well with traction control systems.

az7000'
12-29-2018, 06:33 PM
The high is supposed to be 22 today and snow on the ground... I'll get the measurements as soon as I can!

Midwestdrifter
12-29-2018, 06:36 PM
The high is supposed to be 22 today and snow on the ground... I'll get the measurements as soon as I can!

No hurry. It was 20F last night, and I have no desire to lay on the cold ground myself!

I just got Solidworks installed on my laptop, so I will start modeling the sprinters front end.

Midwestdrifter
12-30-2018, 02:44 AM
Did some rough sketches using dimensions from photos and the internets. Control arms are placed in the same position they are on my van, 2" higher than stock. Differential is the 9.25" GM model. Clearance on the oil pan is tight, but should clear if with the output flanges 1.25" below the frame rails. I can raise it up more, but would likely require moving it backwards, which would consume some of the total angle on the CVs, which is undesirable. The inner tripod joints are limited to around 18-20 deg total, with the outer repezza unit being 40-45 deg or so.

See attached photo. Still using rough or guesstimate measurements, but I am pretty good at those.

The Diff mounts may be a challenge. There may be some stock ones (escalade, suburban) which can be adapted. This unit is meant to be mounted to a frame above it, while in the sprinter the subframe is below and to the sides.

In order to use the factory strut with decent compression travel, I will probably need to lift the front 1-2". However the rest of the world got a lower sprinter with a shorter strut (same travel). Using that unit would eliminate the need to lift the van more than 2" from stock, which would be useful for those who like factory ride height.

I counted the teeth on the sprinters tone rings, 44 gaps.

Midwestdrifter
12-30-2018, 03:44 PM
Looks like torsion bars are 54" long or so. that puts them just behind the B pillar, overlapping the fuel tank a bit. I anticipate that the fuel tank will need moved some, as the Tcase will be a tight fit otherwise.

The torsion bar rear mount will be incorporated into a cross beam that will mount to the body on the sides? I need to look at the dimensions, as I would prefer to anchor to the B pillar area, as that is beefier. There is plenty of room for the cross member, but it it will hang down a fair bit.

The factory trans mount will not fit the Jeep main case. The jeeps use a mount in a similar location, So remaking, or modifying the existing trans cross member shouldn't be an issue. It will need lowered 3-4" to clear the front driveshaft.

AdrianD
12-31-2018, 11:47 AM
I like the front axle project!
Why are you using torsion bars instead of springs? Height issues?

Midwestdrifter
12-31-2018, 02:17 PM
I like the front axle project!
Why are you using torsion bars instead of springs? Height issues?

The Sprinter is a unibody with no coil spring mounts (transverse leaf spring design). Adding coil springs would require a fair bit of modification to the body. I am trying to avoid that. The torsion bar GM suspension allows for that. As I just need a bolt on cross member to anchor the aft end of the torsion bars.

Midwestdrifter
12-31-2018, 07:09 PM
Visited one junkyard today. No 2500 GM vehicles. At least 8 1500 series though. Took a few measurements and photos for reference.



https://farm5.staticflickr.com/4803/46492605552_9ebf387ec1_c.jpg (https://flic.kr/p/2dQoKRs)IMG_20181231_102345 (https://flic.kr/p/2dQoKRs) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm5.staticflickr.com/4810/45630985615_80bc4fe492_c.jpg (https://flic.kr/p/2cwfJgi)IMG_20181231_101141 (https://flic.kr/p/2cwfJgi) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm5.staticflickr.com/4874/46544498621_6f14a96d74_c.jpg (https://flic.kr/p/2dUYHRx)IMG_20181231_101020 (https://flic.kr/p/2dUYHRx) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

https://farm8.staticflickr.com/7846/44727069060_36a1eab399_c.jpg (https://flic.kr/p/2b9nVn7)IMG_20181231_101016 (https://flic.kr/p/2b9nVn7) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

The Rear Torsion bar carrier just uses 1 bolt each side to mount, so making a set of riser brackets to attach to the sprinter should be pretty straight forward. Re-using the facotory bracket and adjusters as well.

https://farm5.staticflickr.com/4905/44727073780_dd65ff17f6_c.jpg (https://flic.kr/p/2b9nWLu)IMG_20181231_102123 (https://flic.kr/p/2b9nWLu) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

Here is a photo with square for scale.

https://farm8.staticflickr.com/7894/44727075720_3f39c99e0b_c.jpg (https://flic.kr/p/2b9nXkW)IMG_20181231_102409 (https://flic.kr/p/2b9nXkW) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

With a few adjustments for what bits I know are different on the 2500, I updated the model. The copper colored A-arm is the factory unit as it sits on my van. The gray one is the 1500 truck unit using GM factory geometry/placement. (see attached photos)

Midwestdrifter
12-31-2018, 07:11 PM
On the strut mounting, I believe I will cut/trim the upper ball joint mount. (see attached photo).

Then I will weld on a bracket with 4 stubs/risers to attach the sprinters strut. The angles look all right, so everything should pretty much line up.

At this point a ride height 2" above stock should fit the diff. However I am not sure if the factory (North american) length strut will clear the outer CV at this height. So that will be the deciding factor.

Midwestdrifter
01-01-2019, 07:17 PM
Started Roughing out the subframe. I am still not sure how I will do the Diff mounts, especially the drivers side. The engine mounts aren't perfectly alignment with the forward cross member. I might need to make an offset/jog to pick them up and still have space for the Steering rack.

To make the steering rack fit well, I will likely need to rotate the input shaft rearward. The GM spindles tie-rack attachment is higher than the sprinter, which means the sprinters steering shaft should be long enough. Clearance is pretty good, so I think the sprinter rack will fit without mods to anything. I think an adapter or custom tie rod might be needed, but thats pretty simple stuff.

owner
01-02-2019, 01:02 AM
Have you considered a ML270 sump? It is a lot shallower than the sprinter sump. It might give you more options for diff/rack/engine mounting if you get stuck.

Midwestdrifter
01-02-2019, 01:07 AM
Have you considered a ML270 sump? It is a lot shallower than the sprinter sump. It might give you more options for diff/rack/engine mounting if you get stuck.

I did give other pans some thought. The Jeep Cherokee OM647 pan is available (at high prices) in the USA. It may have better clearance. Its hard to tell, as the sprinters engine is much farther back compared to the front wheels than most cars and SUVs.

My measurements thus far indicate that the Sprinters oil pan won't be a limitation. It already has a fair bit of clearance for the steering rack on the lower ROW vans.

I have not run into any major snags yet. Which has me (irrationally) worried. :lol:

az7000'
01-02-2019, 04:18 PM
Yeah, I suck, no measurements! Its up to 17 degrees outside this morning. FWIW the torsion keys are the same as the fords but with different indexing. I have one ford and one chevy in mine now as I just cranked them to get rid of the "stink bug" appearance on my chevy. Search chevy leveling kits for more options, lots options for the ride height, I would love to see the guy at the alignment shop someday.

Midwestdrifter
01-02-2019, 08:40 PM
No worries, its pretty cold here as well (20f this morning).

I am still chipping away at the rough design. Made a model of the Steering rack, added bump stops, and engine mount positions .

The steering rack needs to move forward a bit, and rotate backwards some. The Engine mounts are kinda in a tough spot and will need some creative design. They are pretty close to the Steering rack. I may be able to move the rack back an inch or so, just depends on the diffs final position and dimensions. The passenger lower rear diff mount is interfering with the rear cross over. So I will need drop the crossover down, or incorporate the mount into the crossover. Its hard to tell without diff on hand to measure. Plus the pinion angle is dependent on the Tcase/trans positioning. It should be the same as the current trans angle though.

I have made the model such that once I get the final dimensions, I can just update about 30 variables, and the whole thing should rebuild to the exact size.

Midwestdrifter
01-06-2019, 02:42 PM
I got a some more accurate measurements of the 9.25" front diff (thanks mountainhick!).

Clearance is looking quite good at the oil pan, with at least an inch. I could even raise the diff some more, but I don't see any advantages to that.

I have exhausted all the self service junkyards in my area. Still watching them for new 2500/3500s. Also watching craigslist etc.


Mating up with the drivers side diff mounts on the GMT-800 is going to be a bit of a challenge. The later diffs (2012) and some of the GMT-900 2500 diffs use a horizontal flat plate instead of the two eyelet style mounts. So if I can't make it work, those can be sourced. Other than the drivers side mount they are identical in exterior dimensions. The 2012 + models switched from the clamshell style lateral case to a traditional single casting with steel cover.

Some other interesting tidbits. The GM lower control arm has an non-parallel pivot axis. Looks to be about 2 degrees inward. This is not desirable with a strut front end, so I may go with parallel pivot axis (same as the sprinter has). This angle can reduce caster during bump, which is not desirable. The effect may be minimal, but I won't know until I get a bit more information into the model.

mountainhick
01-06-2019, 03:33 PM
The later diffs (2012) and some of the GMT-900 2500 diffs use a horizontal flat plate instead of the two eyelet style mounts.

This 1999 GM800 2500 series Silverado diff has one 2-bolt flat plate on passenger side, single eyelet driver's side

Midwestdrifter
01-06-2019, 03:40 PM
Attached are photos of the later flange mount, and the earlier upper/lower bolt style.

Midwestdrifter
01-06-2019, 03:53 PM
Another few bits of useful info. It looks like the 01-06 1500HD & 07 1500HD CLASSIC GM truck also use the same front suspension as the 2500/3500 series. The torsion bars might use a slightly different spring rate.

mountainhick
01-06-2019, 03:55 PM
This is what was in that 1999 GM 2500. I am not sure if there is a second eyelet under the case:

https://s3.amazonaws.com/powertrainproducts/images/watermarked/z1337a-2.jpg

http://images1.americanlisted.com/nlarge/2000-chevy-silverado-front-differential-50-americanlisted_36582155.jpg

Midwestdrifter
01-06-2019, 03:59 PM
Thanks, that matches what I am seeing on the web.

This document is for installing a lift kit on the GM trucks.

https://s3.amazonaws.com/roughcountry/install/92129700.pdf

On page 6 (photo 12 and 16), they cut off the upper drivers side mount boss, and bolt on a re-positioned mount bracket. This seems like a reasonable approach.

Midwestdrifter
01-06-2019, 06:35 PM
I have an agreement to buy the complete front end off a 02 suburban. $750 and 180k miles. Haven't seen them yet, but looks promising.

mountainhick
01-06-2019, 07:04 PM
I have an agreement to buy the complete front end off a 02 suburban. $750 and 180k miles. Haven't seen them yet, but looks promising.

1500 or 2500?

Midwestdrifter
01-06-2019, 07:04 PM
1500 or 2500?

2500 4x4 with 3.73 gears. :thumbup: It should be basically the same as the silverado/sierra. Shocks and torsion bars are slightly different ratings, but brakes and suspension parts are the same.

mountainhick
01-06-2019, 07:09 PM
Nice. Will be interesting to see if the diff case and mounts are the same as 99 silverado.

Midwestdrifter
01-06-2019, 07:15 PM
Nice. Will be interesting to see if the diff case and mounts are the same as 99 silverado.

Rockauto is showing the same part numbers, so I am pretty certain they are the same part. The diff mounting brackets may be slightly different, but nothing hard to source.

jcmadeintheshade@gmail.com
01-06-2019, 07:37 PM
Thanks to all for this interesting thread that I will follow to the end. There will be no end.

What a shame that MB cannot be more accommodating in providing assistance for this upgrade. Europe and the rest of the world gets it. We do not. I am aware that our DOT requires many such vehicle upgrades to be crash tested before any such technology can be approved of here in the States.

Still, knowing that this is sold everywhere else on the planet and that the MB parts are out there, is frustrating.

Thanks for doing what you can to open up new possibilities for going where most of us cannot imagine going. This forum is invaluable.

Midwestdrifter
01-07-2019, 06:51 PM
Just got back from examining the donor suburban. Based on my rough measurements the major suspension bits match the truck 2500/3500. I am looking forward to getting good models made of all the parts.

I have some good options for the Diff and rack mounts, but I don't want to put too much time into modeling until I have more accurate dimensions of the Control arms, and the Sprinters engine mount placement.

The only major unknown is the strut attachment. I need to get accurate droop measurements from the sprinters strut. It is going to be tight unless I want to lift the van some more (undesirable). If needed I can order some struts from Europe, the shorter strut should get me the compression/droop travel and still clear the outer CV.

Midwestdrifter
01-16-2019, 10:05 PM
Picked up the parts today. A little bit crusty, but its all there. Seems pretty tight for 180k miles or so.

https://farm8.staticflickr.com/7881/45853850195_27e0814a96_c.jpgIMG_20190116_140557 ('https://flic.kr/p/2cRWY94') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

https://farm8.staticflickr.com/7804/39803647733_0e9a5de925_c.jpgIMG_20190116_143836 ('https://flic.kr/p/23Dj6Jv') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

https://farm5.staticflickr.com/4847/46043908844_314032e7e4_c.jpgIMG_20190116_143849 ('https://flic.kr/p/2d9K4Xj') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

https://farm5.staticflickr.com/4816/46043910624_305c44c5fc_c.jpgIMG_20190116_144539 ('https://flic.kr/p/2d9K5u1') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

Getting the torsion keys off the bars was a pain, took about 20 minutes with a 4 pound sledge and air hammer.

A first look shows the lower A-arm pivots are actually offset slightly. The axis are parallel front/back, but they don't share the same width from center.

First impressions are that everything is meaty. Gm is pretty conservative with these 2500/3500 trucks. The brakes and bearings look substantially heavier than the sprinters factory bits. I am going to try and pull one side apart for measurements. From there I will do motion studies in solidworks, and do a rough mockup on the shop floor to simulate everything. I have a used sprinter steering rack, so I can use that without pulling my van apart.

The torsion bars are as follows, this is a 2500 suburban with 6.0 engine.
GK 8615
15528963 (LH)
15528964 (RH)

According to this site they are 8600lb/ft rate, which is a bit less than the max available of 9000. Should be good for a fully loaded van. I do have options as low as 4500lb/ft if needed.
https://www.gmfullsize.com/tech/torsion401.html

Midwestdrifter
01-18-2019, 07:52 PM
Getting some details into the model. Its not easy to get good measurements off the sprinter, especially the upper mount placement.

Ran into a bit of a roadblock. The Sprinters strut body is 15" long. The GM 2500 outer CV is nearly 5" in diameter. (much larger than the 1500 CV). In order to clear the CV and have enough up travel, I am looking at a ride height nearly 4" higher than current, 6" higher than stock. The euro strut is about an inch shorter, which helps. I am going to look at the later sprinter struts. Not likely they are shorter, but can't hurt to check.

https://farm8.staticflickr.com/7834/31847603617_9bc9843965_c.jpg ('https://flic.kr/p/Qwgi16')

https://farm5.staticflickr.com/4803/31847603527_715b38425f_c.jpg ('https://flic.kr/p/QwghYx')

https://farm5.staticflickr.com/4816/46043910624_305c44c5fc_c.jpg ('https://flic.kr/p/2d9K5u1')

Midwestdrifter
01-18-2019, 07:54 PM
I did some rough measuring of the GM upper A-arm. It actually might be short enough to fit in the sprinter wheel well. I added a few sections to my subframe part. This shows some promise. I can use the GM upper A-arms with a riser section on the subframe. This will wrap around the sprinters "frame" rails. I still need to work out how to mount the GM shock. It will take some creative thinking to make clearance for the tirerods, and still have enough meat to support the upper arms.

I also counted the teeth on the GM tone rings. Total 55 teeth. The tone ring is integral to the unit bearing/hub assembly.

Midwestdrifter
01-18-2019, 10:57 PM
Okay, made a quick jig from some scrap wood. The upper A-arm mount just barely fits inside the sprinter wheel well. But only if I push the track width up to about 68-69", that will still require a small clearance window to be cut in the frame rail. Which is not ideal. The 3500 series trucks use a 125mm offset wheel. Which with wheel spacers may allow me to reclaim some of that track width. Assuming the wheels clear the suspension of course...

The CV axles should handle the extra width, but I need to confirm.

Midwestdrifter
01-19-2019, 11:17 PM
Still chipping away. The GM bits are looking pretty good. Here we have normal ride height. The lower A-arm looks weird, as I am too lazy to accurately model the curve it has. Interestingly adding pieces to support the upper A-arm has solved two problems. It has provided a second support for the engine mounts, which were too far back to tie into the front/lower A-arm. It also required me to extend the subframe about 2 inches farther back. This allows room to move the rear cross-over to clear the Diffs rear mount.

You will notice that the engine mount is interfering with the steering input shaft. Not sure what I want to do here. I can cut the diff mounting tab off, and relocate with the aftermarket lift bracket. There may just enough room though.

Midwestdrifter
01-20-2019, 03:01 AM
Finally feel like I made some good progress. I realized I clocked the Diff mounts wrong. The pinion is 10 degrees off from the passenger side mount, and the flats on the case top. So the steering rack just squeaks by now.




Got the rear diff mount dialed in. I am starting with a pinion angle of 5 degrees, with room to go plus/minus 4 degrees either way.



Unfortunately my version of solidworks (2017) doesn't support automatic slot and tab creation! I may need to upgrade... By creating slots/tabs on adjacent bodies, I can essentially assemble/weld the entire subframe without a jig! Other good news, looks like the GM sway bar will bolt to the front of the subframe (similar to sprinters bar).



There is no substitute for hands on. Here is the beginnings of a jig to double check all my dimensions. Eventually I will have upper A-arm mounts and diff mounts.

https://farm8.staticflickr.com/7824/46068178584_c06ea3b79b_c.jpg ('https://flic.kr/p/2dbTsv7')


I haven't decided what material thicknesses to use. For simplicity's sake and costs, I will try to stick with just 2 sizes. Though I may have some short lengths of tubing or bushing stock. Right now I am just using 3/16 sheet stock, and 0.25" bar/plate. If I haven't screwed anything up, I should be able to just change a variable for stock size. Last I checked the subframe was looking at around 60lbs. I am sure another 15lbs will be added before the end. The whole assembly with diff and suspension will weigh at least 450lbs (without tires).

Midwestdrifter
01-21-2019, 08:53 PM
Modeled the sway bar and still beating on the subframe design. The skeleton is done, and now I am adding reinforcement, gussets, etc. The only significant challenge is going to be the drivers side upper diff mount. No easy solutions have presented themselves, but maybe the engine mount can be co-opted somehow. The torque about the diff center is going to be quite significant. Something like 5,000 lb-ft at worst case? I need to crawl under the van and refine the engine mount position with regards to axle centerline. Its about 20F with windchill, so motivation is low...

Midwestdrifter
01-22-2019, 09:26 PM
Refining suspension parameters currently. Ackerman angle should be at least 50%, possibly as high as 75%. I would like 80-90%, but trade offs are the name of the game.

Based on Inner CV angles, 6" of travel should be no problem, as as much as 9" could be possible. With 3.5" of droop I am seeing ~20 degrees on the inner CV. Same for 4.5" of bump.

I am limited on lower A-arm pivot angles by the torsion bars. I am considering a 3 degree angle on the upper pivot. This should provide somewhere around 10-25% anti-dive.

Camber gain is pretty flat through the middle 4.5" of travel, caster gain will be about 0.25 degree per inch with the 10% anti-dive.

I am still stuck on the upper diff mount. At this point I think the best option is to cut off the mount boss, and make a lower mount that attaches to the case bolts/seam. Similar mounts are used for various truck lift kits, not sure if any of them would work though. I can make my own fairly simply. In order to make a template, I will likely need to split the diff case, and take a rubbing of the bolt locations.

I am setting caster at 3 degrees currently. My can has around 2-3 as it sits, with an unlifted van being around 3-4. GM specifies around 1 degree (plus/mins 1 degree). However GM uses a gearbox to drive its center link. These tend to transmit less force back to the steering wheel. With the sprinters rack/pinion I feel that more centering at medium/low speeds is needed to keep driver effort low, especially with bigger tires. If needed There are aftermarket adjustable upper-arms. These use an eccentric pivot for the ball joint, which allows plus/minus 3 degrees of caster and camber adjustment.

It warmed up a bit today, so I broke out the power washer and a couple cans of EasyOff. Most of the grime and some of the rust came off. It was getting old having to wash my hands every time I touched anything...

https://farm5.staticflickr.com/4813/46790729652_8be7b880a4_c.jpg (https://flic.kr/p/2ehJHL9)IMG_20190122_130734 (https://flic.kr/p/2ehJHL9) by J Luth (https://www.flickr.com/photos/129334372@N04/), on Flickr

Midwestdrifter
01-23-2019, 01:11 AM
Changing direction a little bit just to take a break from 3D problem solving. I am running a few simulations of worst case loading. Trying to get an idea if my design and material thickness choices are viable. Here I am simulating a worst case scenario loading of one tire in the lateral direction. 10klbs applied to the wheel edge away away from the vehicles centerline. Everything in red is over the yield strength of mild steel, Obviously some corners are artifacts introduced by sharp corners in the model. However there are areas, especially around the bump stop and upper Arm supports that need some reinforcement. Obviously before I complete the model I am going to add dozens of fillets to sharp corners etc. Dealing with them within the part sketches is a pain, so I like to add them to the completed bodies/solids at the very end.

Midwestdrifter
01-23-2019, 04:17 PM
Still doing some basic math to confirm performance. For giggles here is the turning specs from the van and donor suburban.

Suburban
WB=130"
Turning Radius=22'
Calculated steering angle =29 deg

Sprinter
WB=140"
TR=22'
Calculated steering angle =32 deg

With 29 degrees on the sprinter, and a slightly wider front track, the turning radius is 24ft. This is calculated (and measured) to the front outer wheel. Assuming I can extract the same wheel angle on the sprinter as the Suburban had of course. An extra 2ft larger turning radius seems pretty reasonable really.

Midwestdrifter
01-23-2019, 09:55 PM
Put a few more pieces on my redneck jig.
https://farm8.staticflickr.com/7828/32978596228_27b236811f_c.jpgIMG_20190123_144721 ('https://flic.kr/p/SfcVGG') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

Steering angle is somewhere around 70 degrees total. It isn't symmetric though, so with the wheels connected its probably around 60 degrees.

https://farm8.staticflickr.com/7910/46801916092_8cb1ba3375_c.jpgIMG_20190123_144620 ('https://flic.kr/p/2eiJ46N') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

The Gm stops are not linear with suspension travel, so the farther from the natural ride height you get, the smaller the allowed angle is.

The digital angle finder has been indispensable. Camber gain is pretty flat, less than 0.5 deg per inch.

https://farm8.staticflickr.com/7817/46801917922_cbcb4ae40c_c.jpgIMG_20190123_145112 ('https://flic.kr/p/2eiJ4Dm') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

GM was nice enough to put a few surfaces that are perpendicular to the kingpin axis. I am aiming for at least 2.5 deg, and no more than 3.5 deg of caster. This is roughly the range the sprinter uses.

https://farm5.staticflickr.com/4842/32978598808_d65ae6b836_c.jpgIMG_20190123_145133 ('https://flic.kr/p/SfcWtb') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

The jig has already proved its value, as I needed to adjust my upper arm pivot nearly 1/3 of an inch.

Midwestdrifter
01-25-2019, 01:27 AM
Still trucking on the Subframe. Lots of reinforcement, and a couple rounds of load simulations. It is over 90lbs now... Rear drivers side diff mount is pretty much finalized. I roughed in the rack mounts. I need to work out a method that will allow me to adjust its angle/position without needing to cut the bracket up (during fabrication) as I anticipate the final positioning will change when everything is bolt up. I am trying to incorporate slots and some play in the various attachments. This should allow some fudge-factor in both assembly, and my design.


After some head scratching I think that I can re-use the factory passenger side mount. I am going to flip it upside down, and left to right. All 4 studs will be pressed out and reversed.



The drivers side forward mount is gonna have to come off. I will make a bolt-on bracket, and hopefully pickup some of the front cross-over. It will need to be a bolt on attachment, so the diff can drop out for maintenance.

My current plan is to use a normal front driveshaft (2 UJ), and get the diff and Tcase angles matched. Though maybe I should just plan on using a CV driveshaft and having the diff tilted up more? Say 10 degrees? I guess I need to mock up the driveshaft to see what the angles will look like. Its tough to estimate as I don't have the Tcase bolted up. Which reminds me, I need to get a trans housing and adapter casing...

OrioN
01-25-2019, 01:42 AM
:popcorn:

Midwestdrifter
01-25-2019, 11:38 PM
The factory bracket would either require a 6" riser (and be pretty close to the bell housing) or interfere with the rack mount. So I will just fabricate a bracket. The slots allow for a combined adjustment of plus/minus 4 degrees. I will use some weld-in urethane bushings at both ends. If you look close you might see slots/tabs starting to appear. Its time consuming and fiddly, but will pay dividends when i go to assemble everything.


I am trying to get the wheels nearly centered in the wheel wells. So I need to get some measurements of where the subframe locating bolts are with respect to the wheel center. Not really possible to do with the factory subframe in place. I am a bit concerned that the 4 bolts are going to interfere with the major lateral plates of the design. If so I am going to have to be creative I think.

Midwestdrifter
01-26-2019, 06:12 PM
Rounds of refinement are rapidly finalizing the design. Clearances are coming into focus, and I am double checking all my measurements. I am aiming for .4-.5" of clearance around the diff and output flanges. Still adding tabs... slot/tab groups don't mirror across different bodies, which adds a fair bit of work. PS diff bracket is finalized.



Final tasks are:
Rail mounting bolt locations
Steering rack mounts
Bump stop calibration (for ride height)
Engine mount towers (location, angle)
Drivers side forward diff mount

The rail bolts will have to wait until I tear the van down. I have a used rack in storage I can measure. I need a 2500 bump stop to put on my jig to adjust its contact at ride height. The engine mounts will also have to wait until I drop the MB subframe.


Looking forward. Here is the jeep 242 tcase I grabbed at the local yard.

https://farm2.staticflickr.com/1881/44451403281_ec20e2be6a_c.jpgIMG_20180903_095638 ('https://flic.kr/p/2aJ24wR') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

https://farm2.staticflickr.com/1883/43734149844_d47f354183_c.jpgIMG_20180903_110413 ('https://flic.kr/p/29CCX5h') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr



Here is what the MB rack looks like.

https://farm2.staticflickr.com/1899/44576360152_175a7fb772_c.jpgIMG_20180907_182606 ('https://flic.kr/p/2aV4uRE') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr


Other major components I need.
Wrangler NAG1 to NP/NV adapter case and shaft
Jeep NAG1 main case
Custom front/rear driveshafts. The rear may be interesting, as MBs input flange is not common.
Tcase shift handle and cable (should be pretty simple)

In addition to the subframe, I need to design/fabricate the following.
Drop/mount brackets for GM torsion carrier
Drop spacers for MB trans crossmember
Adapter for Jeep trans isolator/mount to MB cross member
Tone rings for the outer CVs

Unknowns
Tcase to fuel tank clearance

Midwestdrifter
01-27-2019, 09:50 PM
I split the diff case. I was curious on what I would see, as the oil had a fair amount of metal in it. I noticed excessive backlash as well.

https://farm8.staticflickr.com/7873/46171206514_d978f8cf28_c.jpgIMG_20190127_111337 ('https://flic.kr/p/2dkZv7J') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

https://farm5.staticflickr.com/4914/46844120572_9281282dd0_c.jpgIMG_20190127_111356 ('https://flic.kr/p/2ensn2f') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

Here's the source of the debris. Drivers side carrier bearing. The R&P has some wear, but looks re-usable. The pinion bearings also feel fine. I think a new set of carrier bearings, new seals, and new axle bearings should do the trick. Interestingly, the passenger side carrier bearing was fine.

https://farm5.staticflickr.com/4893/39931259763_8f60b5fa6f_c.jpgIMG_20190127_113654 ('https://flic.kr/p/23QA9kV') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

Another reason for splitting the case was to allow me to take a print of the case bolts.
https://farm5.staticflickr.com/4866/39931260333_010495e460_c.jpgIMG_20190127_115733 ('https://flic.kr/p/23QA9vK') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

Here is a rough bracket in CAD.

Midwestdrifter
01-28-2019, 04:44 PM
For reference later, the 2002-2003 V8 Grand Cherokee with select-trac, uses a 242HD transfer case. This case has a 27 spline input shaft, and 32 spline output shafts. It uses the wider 1.25" drive chain as well. I am going to keep my eyes out for one. They are not terribly common though.



I think I have something workable for DS front diff mount. plus/mins 4 degrees of adjustment. I used 2 1/4" plates for the diff side of the bracket. I am trying to spread the load on the aluminum case. It seems pretty beefy in this area though. I am using the same weld-in urethane busing as the PS mount. I thought about just using a turnbuckle. Finding a bolt-eye turnbuckle that was short enough proved elusive. I am going to print out a template of the bracket at 1:1 scale, and make sure it fits the diff. Being a casting, the flange is not terribly even or symmetric.

Refining the models of the rack and related areas of the diff casing. The input shaft on the rack has an rearward offset. With the diffs upper mount boss removed, there should be 1" of clearance to the racks casting. I am unsure if the hydraulic lines are going to clear, as they have large stress relieving loops (~4" diameter). I wan't to avoid custom lines, but may not have a choice. They look like metric flare, so should be easy enough to locate. Its a complete pain to measure my van with the skidplate installed, so that may have to wait a while. I still have about 10 tab/slot groups to create, and 2-4 gussets for the engine mounts. Speaking of skidplates, I have a 1/4" aluminum one on the van. If possible I am going to try and incorporate it into the design. Should be simple enough with 4 bolts. The issue is that the diff hangs down about 3/4", and the rear diff mount about 1". Not sure if I want to give up 1" of ground clearance.

I am going to crawl under my van when it warms up a little and do a mockup of the torsion bar location. I need to get a feel for how the trans crossmember, Tshaft bracket, and fuel tank are going to line up. I have been mulling the idea of fabbing a custom larger fuel tank. Something in the 150L/40 gal range. Which would make good use of the factory tank location. I could easily clearance that for the Tcase. Should be pretty simple CAD work, and a day or two welding aluminum. Of course I would need to get a spool gun (or a decent welder).

Midwestdrifter
01-29-2019, 11:37 PM
After looking at a the GM upper arm placement more closely, I decided to increase the anti-dive more. That meant reworking my sketches, and doing some in-place bends. Looks like a 2x2" clearance hole will need cut behind each upper arm bushing. Just not enough room for full camber adjustment without it. Engine mounts are being a pain, So I am going to do a couple of "easy" bends to get the bolt clearance I need. Of course bending 1/4" sheet is rarely easy without a press brake. Another milestone, the subframe has broken 100lbs. 120 to be precise. That includes the Diff mounting brackets, but does not include the weight of the weld beads. This should be pretty close to the final weight, though I have a bit of tweaking left to do on the engine and rack mounts

Midwestdrifter
01-30-2019, 12:05 AM
A quick correction. Early I said the 242HD had a 27 spline input. That was incorrect. All jeep versions of the NP242 use a 23 spline input. The regular 242 uses a 26/27 spline output, while the HD uses a 32 spline output front/rear. There is a hummer version of the 242HD, and it has a 32 spline input shaft.

The wrangler with NAG1 uses a 23 spline input with the 241. Wranglers (rubicon models?) with rock-track NP241OR and NAG1 use an unusual 26 spline input. This is not compatible with any version of the 242 I know of. Other models of jeep with 4x4 and NAG1 should use the common 23 spline input. There are several lengths of input shaft on the NP242, the Jeeps normally use the "short" shaft.

Attached below is a chart with the input torque ratings of various NP/NV transfer cases.

Midwestdrifter
01-31-2019, 03:38 PM
Tossed a quick shock part into the model. Looks like it will fit without issue. I was a bit concerned it would contact the upper arm at full droop, as I can't mount the top as far inboard as the suburban does. I was considering designing for both a Bilstein B8, and possibly my Fox remote-resi shocks. I need to measure the fox units, but they are about the right length and stroke, so with a re-valve I can re-use them. Both shocks will need an upper mount fabbed. I will just bolt the mount to the wheel well wall. This area is right next to the strut mount, so I can tie into the heavier structure around that.

Working on the bump stop and tbar clearance. I am going to need to update my jig to get more accurate measurements of bumpstop positioning. Given the stop also does duty as a progressive damper, positioning is critical to good ride quality.

Double checking the track width after a few changes. It shows as just under 69" with suburban factory wheels (28mm ET). I was hoping to stay under 67" (65 stock), but any narrower wouldn't work with the frame to upper arm clearance. I may be able to use a different offset to get the track width narrower. 50mm would do the trick. Additionally I am aiming to set the CV angles near zero at rest. While I do have more lift on tap if I need it, I am going for reliability, and the less angular displacement the better for longevity.

Midwestdrifter
01-31-2019, 11:07 PM
Working on bump steer today. As anticipated, its quite sensitive to positioning of the tie rod ends. The sprinters rack is about 1" shorter than the GM center link. I ended up moving the rack up about 3/4". I am not 100% on the outer tie rod placement, as its a pain to get an accurate center measurement with greasy boots and unlevel floors. Right now my model is indicating 0.21 deg toe (per wheel) at 4" droop, and 0.14 deg at 3" of bump. Camber is 1 degree in droop and 1.2 deg in bump. I may move the upper arm pivot some, but I'm not sure yet. I could fabricate a 1/4" spacer for the MB inner tie rod. That might reduce the bump steer some more. For reference 0.2 deg per wheel is a tie rod movement of about 0.020" it is looking like 7" is about the most GM designed for. I just need to decide if I want that equal bump/droop, or if I want to have more travel in one direction or the other.

I took some measurements of the inner fender/strut mount area. Plenty of room to mount the upper shock bracket. The question is if I want it floating, or attached to the subframe? Obviously it will need anchored to the fender/body, likely with a few bolts into the strut brace.

Midwestdrifter
02-02-2019, 05:54 PM
Still chipping away. I discovered an error in the steering arm placement. Must have transposed a measurement somewhere. So my ackerman numbers were off quiet a bit. The only solution is to move the diff and rack some. I shifted the diff as much as I could, and moved the rack as well. Dropped the whole subframe another half inch.

To get the ackerman numbers I need, I am going to use a slight offset spacer on the end of the rack. About 0.5-.75" long, shouldn't interfere with the boot, or cause undue stress on the rack. With the sprinters rack being about 0.75" shorter than the GM center link, and the track being 1" wider than GM spec, I have about 1-1.5" of width to add a spacer. This will allow me to use the GM tie-rods without modification.


The ackerman angle I need at full lock is about 6-7 degrees (total toe out). With the changes the model is showing about 60% of that at 4.5 degrees. Not perfect, but good enough. The van will tend to "push" a bit at full lock on pavement (parking lots etc). GM had about 80% ackerman in their design. On the 1500s they have more, but the larger brakes on the 2500 reduced this number, despite GM moving the centerlink back some.


Clearance at the rear lower A-arm bushing is tight, so lots of rework going on here.

Midwestdrifter
02-03-2019, 12:09 AM
Just for completeness, there are 5 options for front diffs on the GM 9.25 IFS axle.

1: Open (stock)
2: E locker (selectable 12V control).
3: Lunchbox Style (mechanical, locks on RPM difference during wheel spin)
4: Air locker (ARB, compressed air control via switch/solenoid)
5: Helical Gear LSD (torque biasing, does not function with one wheel lifted).

The Helical unit is cheapest, at around 600$. ARB units are around 1000-1500$.

https://speedmaster79.com/chrysler-...ine-torqueworm-lsd-limited-slip-differential/
https://eastcoastgearsupply.com/i-2893836-gm-aam-9-25-ifs-arb-air-locker-rd197-33-spline-all.html

I am not sure if I want/need a LSD in the front. The helical/true-trac units are not very expensive, and I will be resetting the preload and backlash already, as the bearings need replaced.

Midwestdrifter
02-04-2019, 08:44 PM
Made a lot of progress. I finally feel that I have something that will meet all the requirements.

At full droop I need to check the upper BJ articulation limit. If I am over in droop, I will drop the upper A-arm pivot 3/4". Bump steer is nearly zero, Ackerman is 65%. Track width is 65-68" depending on wheel selection. Shown is the sprinter wheel, but a adapter would be needed. GM Dually wheels (16x6.5) with 120mm offset could be used with a spacer to set track width anywhere between 65-70" as desired. Total travel is 7", and is approximately symmetric. More might be possible, but I haven't put the CVs through their range to see what happens.


Plenty of minor design work left, but the geometry and clearances are all there (at least I think so).

The torsion carrier may require modifications. On the Passenger Side frame rail is positioned well, so a drop bracket/link should be easy. On the DS the fuel tank covers the frame rail. There is about 10" free to the outboard of the fuel tank (my grey water tank lives there currently). Any bracket that connections to the frame rail would need a ~8" offset to clear the factory fuel tank. The carrier will just clear the fuel tank. I may cut an inch of height off the carrier, and reinforce with a piece of tubing for the sake of ground clearance.

Midwestdrifter
02-04-2019, 08:46 PM
I was scoping for wheel speed sensor and tone ring placement. There is enough room to wrap the outer CV with a tone band.

The Diff output flanges have a bit of clearance. I may be able to weld a tone wheel on the back side, and attach the sprinters WSS to the diff case. The sprinters sensor is about 3" long, so clearance will be tight. I do believe the sensor can tolerate a 2-3 degree non parallel. I am not sure how much play the flanges have. The Sprinters WSS can tolerate ~.03 gap, maybe .060". I guess I need to put the diff back together and check!

Ignat
02-05-2019, 03:06 PM
Midwestdrifter
I am new with photos , if this one shows , let me know ,I will send more detail photos
This is what Allrad Ighlaut 4x4 conversion looks like on the T1N

https://1drv.ms/u/s!Aqt6uz8k6DY-hzRxelGMUfqeXJsm

Midwestdrifter
02-05-2019, 05:17 PM
Midwestdrifter
I am new with photos , if this one shows , let me know ,I will send more detail photos
This is what Allrad Ighlaut 4x4 conversion looks like on the T1N

https://1drv.ms/u/s!Aqt6uz8k6DY-hzRxelGMUfqeXJsm

Thanks for the photo. I have attached it to this post for convenience.

Midwestdrifter
02-05-2019, 09:28 PM
Laid under the sprinter with my square and ruler for a while (too long really, the neighbors were giving me the stink eye...). The sprinters lower A arm isn't quite symmetric, so I need to adjust the engine mount placement. I also got rough measurements for the 4 mounting bolts. Surprisingly they clear all my vertical structure. I did need to add one access hole for tightening the front one. You will also note the engine mount is narrower. I am not sure if I will recreate the sprinters subframe locating stud. I think I will stick with 1/4" long slots, that way I can adjust subframe positioning for optimal fender clearance and engine position. 32" tires just barely clear the rear of the wheel well.

The shock tower looks pretty good. I need final measurements for the GM shock length and bushing height, and to verify on the jig. I will postpone final adjustments (fillets, tab/slot etc) until I work out the Tbar carrier. So moving on to that and tone rings tomorrow maybe.

Midwestdrifter
02-06-2019, 04:57 PM
Reassembled the diff and checked the flange end play. Measured about 0.03" on both sides. My experience is that that is about the max the ESP/ABS module will tolerate. Looks promising though. The drivers side has about 2.9" of space for the sensor to mount, which should be enough. I figure a tone ring around 6.4" diameter on the drivers side, and maybe 4" diameter on the passenger side, both welded to the back of the output flange. I may need to use slightly shorter bolts on the flange. The PS I can just weld a bracket onto the axle tube, and use the MB spring collar to hold the sensor in a matching 5/8" diameter tube. On the drivers side I will need to bolt or bond to the case somehow.

Here's a first crack at a Tbar carrier bracket. With the fuel tank moved back 3 inches or so, I should have room to tie to the outside of the frame rail. Drilling the bolt hols will be fun though. The filler pipe is in this area, I think it can be moved enough to fit the bracket though. I am using the same 1.5" weld-in bushing as the diff mounts.

Given that the carrier will hang down 3" below the fuel tank, I will likely need to create a narrow skid plate that ties into the trans cross member. Otherwise it would be fairly easy to catch the carrier on uneven breakover, and mess it up.

Midwestdrifter
02-07-2019, 02:21 AM
Some useful info on NP input gears on this site.
http://www.novak-adapt.com/knowledge/np-nvg-input-gears


It looks like all the 24 and 23 series Tcases (not counting 241OR) use the same basic design input gear. All that needs matched is the gear cut style (bevel vs ?), Bearing shoulder, and shaft length. I need to check to see what length of shaft the wrangler 241+NAG1 uses. I think its the short one.


Some more info on the chains used in 242 cases. The goal is a 1" or 1.25" wide 1/2" pitch rocker chain. 3/8" pitch chains are not nearly as strong.

https://www.naxja.org/forum/showthread.php?t=1122820

I think that roller rockers instead of roller pins make the chain stronger, based off of this page ('http://www.emersonindustrial.com/en-US/powertransmissionsolutions/products/drive-components/chain-and-sprockets/inverted-tooth/Pages/default.aspx'). The European 242(ECE) came with rockers, I think I will start pounding down that path.

Some math:
Roller Pin
____
Width | Ultimate Tensile LBS - 3/8" Pitch | 1/2" Pitch
1" | 3750 | 7500 < Current Standard Chain
1.25 | 4690 | 9300

Rocker Joint
____
Width | Ultimate Tensile LBS - 3/8" Pitch | 1/2" Pitch
1" | 7500 | 10,000 <- Euro Case
1.25" | 9375 <- 242HD/242D | 12,500

So basically the rocker jointed chain in 1" with 1/2" pitch out of a 242ECE will be stronger than the 242HD 1.25" x 3/8". (HV-061)

Here's the document ('http://www.rsgear.com/catalogs/borgwarnercat-2007.pdf') I used to find info about the pitches/widths of chains.


https://www.novak-adapt.com/images/graphics/new_process_morse_chain_pin_types.jpg

http://www.novak-adapt.com/catalog/transfer-case-parts/np-242-parts

The H1 uses.5033 Pitch x 1-1/4 W x 72 links, rocker pivot. The euro 242 uses .5033" pitch rocker joint x 1" wide x 72 links.

It looks like the strongest chain that's easily found is the Jeep WJ. That 242 variant uses a 1.25" rocker chain with 3/8 pitch. Which puts its tensile strength at 9300lbs. Which is in the same ballpark as the H1 at 12,500lbs. I believe on V8 WJs had this 242 variant (242HD badged).

Given this info, I am leaning towards a WJ 02-03 4.7L V8 NP242HD (selec-track only). This should have the 1.25" 3/8 pitch rocker chain. Then I will replace the input planet set with a 6 planet version. If necessary I will swap the input gear. The splines will match the Wrangler NAG1 adapter, but I don't know which length of shaft it uses.

Edit: looks like 98-00 (possibly 01-04 as well) Durangos used the NP242D, which is essentially the same as the jeep 242HD. Most likely easier to find as well.

Midwestdrifter
02-07-2019, 02:43 AM
Swapping the wider chain and 6 planet set into a 231/

https://offroadpassport.com/forum/showthread.php?p=34312&highlight=transfer+case+231#post34312

It appears only 231c and possibly 241c have the 6 planet assembly.

Jeep was really bad about labeling the 242HD, sometimes its 242J, 242 WJ, or 242JHD. the only way to tell for sure is to count the output splines.

Midwestdrifter
02-08-2019, 03:53 PM
Updated my jig, and put it through the range of motion. 3.5" of droop and 5.25" of bump. That is just about the limit of the upper BJ mount. The axles have more articulation, so another inch might be possible with some clearancing of the upper arm, or a high angle BJ.

I am not sure if I can get all 5" of bump, as the fenders might interfere, I doubt it though, at least with 30-32" tires. I am considering increasing the ride height a bit, to get the travel more symmetric.


The guys over at Vancompass built a 4wd sprinter using the ML torsion front end. Some interesting photos of their approach. The GM torsion bars are a bit shorter, but I am considering bridging between the Tcarrier and trans crossmember.

With 8.75" of travel at the wheel, I get about 4.7" of travel at the shock. Bilstein B8-5100 series have 4.46" of total travel. Not quite enough. Looks like I need to adjust my shock tower up about 1". The B8-5160 (remote reservoir) units have 5.45". The remote resi units are about 150$ (not adjustable).

Midwestdrifter
02-23-2019, 06:09 PM
Put the Tbar and A-arm on the floor. GM has some interesting angles. The Tbar is not parallel to the arm pivot. It angles in about 2.75" over its length. GM also has the the lower pivots non parallel (left to right). Instead the front is narrower than the rear. With my current placement the lower pivots are parallel. This results in the rear of the Tbars being too narrow for the factory carrier. Right now its about 28" center to center, with the factory carrier at about 33.5" center to center.

https://farm8.staticflickr.com/7821/47187924201_8bb8da84c0_c.jpgIMG_20190223_111007884 _HDR ('https://flic.kr/p/2eTQrS2') by J Luth ('https://www.flickr.com/photos/129334372@N04/'), on Flickr

My options are to narrow the factory Tbar carrier to fit. Or to move the front pivot inwards by 1" or so per side. The downside to this is that it introduces a small angle between the bushings and subframe. Bending the plate to align is not really an option with the subframe being mostly parallel planes.

I am not sure why GM would use non-parallel lower pivots axis in this application? I don't see it providing any useful geometry changes either. It may just have to do with convenient mounting locations.

Midwestdrifter
02-23-2019, 08:35 PM
It will take a 1" shift (per side) of the front lower bushing/pivot point. This equates to a 3 degree (per side) change in the axis. The outer tie rod joint shifts forward 0.7". Unfortunately this also means a 3 degree increase in the static CV angles. Not sure if this is acceptable or not, so if I go this route the diff may need to move.

Shortening the Tbar carrier is not difficult, and I think there is enough room for the 3 degree angle on the keys.

Hmm. I think I am leaning towards shortening the carrier. I made a few changes to my carrier drop bracket for a shortened carrier. I am also questioning weather its worth having rubber bushings on the carrier mounts at all. The little bit of rubber on the factor ones isn't going to do much. Obviously they went away from the big rubber bushings used on the 1500 because they can't handle the extra weight and abuse. Doing away with rubber bushings for NVH concerns means I can weld a trailing beam between the trans crossmember and the Tbar carrier. Which would make a very convienient place to put a light duty skid plate.

Patrick of M
02-24-2019, 02:58 PM
Thanks for keeping the updates coming. Youíve got me convinced, Iíll never try to convert a T1N to 4wd ;)

Midwestdrifter
02-24-2019, 03:06 PM
Ha! I am doing the hard part. Though some assembly is required!

az7000'
02-25-2019, 04:25 PM
I feel like I could apply for some engineering credits somewhere for reading this and I owe you tuition! Fizzy yellow tuition on me if you make it through Flagstaff sometime.

Amazing work!

AdrianD
02-25-2019, 08:38 PM
It's been a clusterfumble on my side to organize with my friend and gather all the parts. I have the WJ CRD transmission case and output shaft. I still need the adapter transmission to transfer case adapter and the intermediate shaft. If you're still going this route I'll disassemble the transmission I have and then get the two remaining adapters.

Midwestdrifter
02-25-2019, 08:42 PM
It's been a clusterfumble on my side to organize with my friend and gather all the parts. I have the WJ CRD transmission case and output shaft. I still need the adapter transmission to transfer case adapter and the intermediate shaft. If you're still going this route I'll disassemble the transmission I have and then get the two remaining adapters.

That is still my plan. The jeep parts are my best option I think. I am plodding along, so at your convenience. Life happens! No pressure.

Thanks!

Midwestdrifter
02-28-2019, 12:08 AM
I feel like I could apply for some engineering credits somewhere for reading this and I owe you tuition! Fizzy yellow tuition on me if you make it through Flagstaff sometime.

Amazing work!

Sure, I am always down to meet the locals. :thumbup: Not sure when we will next be out west though.


After some thought, I decided to incorporate GMs non-parallel pivots. It was a bit fiddly, but I think everything clears now. Its going to be a bit tough to pull the bushing bolts down tight the first time, as the surfaces as 3 degrees from orthogonal. A fair bit of material needed removed to clear the front mount as, the front leg of the A-arm is a nearly straight run from the BJ. Of course with the wheels moved foward a bit, the subfram mounting holes may interfere with some lateral structure. Grrr. I won't know for sure until I drop the factory subframe for measuring.


The wheel flange width is now 71.26" wide. I widened the LCA pivots by 1" total, and adjusted the angle so the torsion bars line up with the factory carrier. I moved the UCA pivot out about 3/8". The clearance hole in the sprinters frame will be much small now.

Supposedly the factory suburban wheels are ET 28. Not sure if believe the internet though. That would put my track width at 69". That's too wide for my fenders, with the factory track being around 65". GM uses the same wheel pattern on the savanna and other 2500/3500 series trucks. I see offsets around 120mm. So with a 60mm spacer, I can set the track width around 66". Assuming the wheels clear the suspension of course.

The tie rod placement is just about perfect with the 3/4" offset rack spacer. I still need to design it, hopefully I can retrieve my spare rack this weekend, and measure it.

The bumps steer is very sensitive to tie rod position. So I anticipate needing to adjust the rack by plus/minus 3/8" during the final assembly. So I need to figure out how I want to accomplish this. I need some angular adjustment to position the steering shaft as well, so it may be best to just order a couple different brackets with different placement, and include slots of the angular adjustment?

I did some more measuring. I am going to lengthen the wheelbase by about .75". This will allow me run a larger tire if desired. It also places the 8x mounting bolts and engine mount towers in ideal locations. Not my photo below, but you can see the factory tire placement. The front plastic bumper is much easier to trim. I have a steel bumper with better clearance though.

Not my photo, but gives an idea of clearance with 31-32" tire.
https://sprinter-source.com/forum/attachment.php?attachmentid=108594&d=1551193774

I think I have decided to make the rack mounts in two pieces. I will put a slot for about 1/2" of vertical adjustment. I will use spacers under the rack mounting bolts to adjust steering shaft angle.

One issue I noticed is that the steering rack can't be removed with the tie-rods in place. At least not with the Diff installed. Not a huge deal, but will add some complexity to that service. Currently the sprinters rack can be dropped with the rods in place. Though it required removing the LCA support plate, and some serious Yoga.

Midwestdrifter
03-01-2019, 03:44 PM
I saw a suburban build with coilovers. That got me thinking, and I may be able to modify the shock tower to handle the load.


It looks like I have room for up to about 3.1" OD spring. The stock lower shock mount is 1.3" wide, and the bolt is ~13mm. Which roughly matches the bearing lowers on the fox 2.0 coilovers. I see some kits from BD that use a fox factory series, but I think that needs a new upper Arm to clear the larger spring?
https://4x4.fatbobsgarage.com/chevr...057.aspx?utm_medium=cse&utm_source=googlebase

Springs for the fox 2.0 (2.5" ID spring) are available up to 1000lb/in. That should be enough, but I need to do some maths.


Coilover units are as cheap as 200$ each (plus spring). It might be worth it for the better ground clearance (No Tbar carrier). I don't particularly wan't to mess around with the fuel tank for a carrier bracket either. The big question is making an upper mount that can take the very significant loading. I don't have much meat to anchor to, as the CV clearance holes are in the same rough position. Though I can extend a leg up to the corner brace for the sprinters factory strut boss.

Some rough math puts the desired spring rate 800-900 lb/in with 5" of shock travel. Preload would be in the .7-1" range. I see springs up to 1000lb/in, so I have some wiggle room.

For reference my van will have about 3700-4000lb (max) on the front axle. Thats a corner weight of 1850. Unsprung weight is about 65lbs for wheel/tire, and 50-80lbs for suspension/brakes. The motion ratio for the GM A-arm is about 0.59:1. My current model has the shock at 13 degrees from vertical, maybe a touch more in the lateral plane.

mountainhick
03-02-2019, 01:39 AM
I'd thin coilovers would be preferable also because of the myriad of options for tuning spring rate and setting ride height without the problems of cranking torsion bars.

There sure are plenty of 1500 series coilover mods/kits. I have only seen one aftermarket 2500 series setup, but for 4.5 and 6" lift.

Might be helpful for bracket ideas:

https://www.youtube.com/watch?v=79jlP5Yn5KE

Midwestdrifter
03-02-2019, 02:44 PM
Spent a bit of time reworking the model for the proposed coilovers. I don't see any reason why a 2.0" coilver with 3.5" OD spring wont' fit. At 5"+ of bump the upper arm would just barely kiss the spring. Good enough for me!


There is still plenty of clearance for a longer shock assembly. Not much point with only 8-9" of travel with the factory CVs anyways. I have one through bolt going through the vans frame rail, and there is enough space that I can put a couple small bolts into the strut brace if needed. I dont think they will be. The shock is at around 17 deg from vertical, so the non vertical component of the strut load will be minimal. There are 3-4 companies that make a coilover that should fit.



There really isn't much room for the GM bumstop. I could do away with the progressive damper part, and use a rubber bushing on the shock shaft. Then retain the final hard-stop. Or maybe remove it completely. That would reduce the weight and complexity of the subframe. I would guess the coilover can handle it.



Axle clearance is close, but doesn't drop under 1/4" at full lock/bump.


Based on my measured CV angles, max bump is tomorrow. Assuming the upper BJ doesn't bind. That is a lot of bump. 5.25 from "static", with 3.75" droop. 9" is good stuff. I am using my max CV angles as 20 deg for the inner, and 20 deg (plus 28 for steering) on the outer.


Based on my model 9" of wheel travel equals almost exactly 5" of shock travel. I should be able to get most of that, but bump and droop stops will eat about half an inch really.

Midwestdrifter
03-02-2019, 02:51 PM
I'd thin coilovers would be preferable also because of the myriad of options for tuning spring rate and setting ride height without the problems of cranking torsion bars.

There sure are plenty of 1500 series coilover mods/kits. I have only seen one aftermarket 2500 series setup, but for 4.5 and 6" lift.

Might be helpful for bracket ideas:

https://www.youtube.com/watch?v=79jlP5Yn5KE


The 2500 lower arm uses a different shock attachment. It has a clevis/bracket bolted to the arm. I don't think the stock bracket is heavy enough, but it would be simple to make a heavier copy out of 1/4" plate. That would easily accommodate the 1/2" bushing used on most coilovers. It may be easier just to weld a couple doublers to the factory bracket, though its 13.1mm or so, not quite 1/2" bolt.

https://farm8.staticflickr.com/7810/46533471704_d7f178fc6e_c.jpg (https://flic.kr/p/2dU1cWh)

mountainhick
03-02-2019, 03:54 PM
The 2500 lower arm uses a different shock attachment. It has a clevis/bracket bolted to the arm. I don't think the stock bracket is heavy enough, but it would be simple to make a heavier copy out of 1/4" plate. That would easily accommodate the 1/2" bushing used on most coilovers. It may be easier just to weld a couple doublers to the factory bracket, though its 13.1mm or so, not quite 1/2" bolt.

https://farm8.staticflickr.com/7810/46533471704_d7f178fc6e_c.jpg (https://flic.kr/p/2dU1cWh)

Nice when a detail is that simple! That bracket really simplifies things compared to the 1500 shock mount. And if you need to, fabbing another bracket would allow adding offset which may improve clearance.

Midwestdrifter
03-02-2019, 05:11 PM
The fox 2.0 shock is a tight fit no matter how you slice it. But it does appear to fit nonetheless.

I snagged a fox 2.5 coilover model and modified it to approximate the 2.0 coilover. It depends on spring OD (depends on rate), but it looks pretty good. The factory UCA has a little bit of contact at full droop. Easy enough to rectify with a die grinder and welder.


The factory bumpstop has to go. So I will just make one integral to the shock.


Just a little contact at full bump. Looks like about .2-.35" needs removed from the fillet/edge area.


I don't think I can move the lower mount forward any farther, as the axle shaft is quite close. I may be able to shift the lower mount backwards slightly, and then shift the upper mount forwards. That may get me less interference with the upper control arm. Given how beefy these UCAs are, I don't have any qualms giving them a light trim to fit.

Midwestdrifter
03-04-2019, 12:40 AM
Repackaged the GM bumpstop. Not quite what GM intended, but should do the trick.

I shifted the shock to nearly vertical in the front plane. I also moved the UCA forwards to get the caster back into spec. Good news, no more interference with the UCA. Now obviously there is a fair bit of camber adjustment built in, so at max (GM allowed) camber adjustment, the UCAs would need trimmed. That should only be necessary at low ride height, or if I totally screwed up some measurements somewhere.

The best choice would be a lower motion ratio, and a 14-16" spring. I could possibly package a 6.5" travel shock. I don't see any simple way to move the shock farther outboard. I could maybe get another 1/2", but any farther would require a custom LCA.

My motion ratio is 0.596:1 or 1.67:1 Ideally it would be around 1.5:1. I could get that down to maybe 1.6 without major changes. Not ideal but GM thought it was an acceptable trade off for on-road usage.

I was looking at springs in the 700-800lb/in range. With silicon alloy wire, the solid height for a 2.5"x12" spring is about ~6". I need 4.55" of shock for 8 at the wheel. With .75" of preload, that leaves 6-4.55-.75 =0.7" before solid. With decent thrust bearings would binding be an issue on a coilover (non strut)? So the 5" travel Fox units should work for 8" of wheel travel. If more travel is desired a 6.5" shock will fit in the wheel well, but the strut tower bracket needs significant trimming. The UCA would also need trimmed.


I will give the 6.5" travel fox coilovers a look. They cost about the same. I would need to remove most of the MB strut tower lower brace, but thats just spot welds and adhesive.

I was looking at the fox 2.5 factory series. They might fit with an offset lower mount bracket. Height is cutting it close. They would probably need a high clearance UCA. BDS makes them for its coilover kits, so they do exist, but are likely quite expensive. I don't think these are for me, but they would provide the ultimate ride.

Midwestdrifter
03-05-2019, 04:15 PM
Finally retrieved my spare steering rack. I should have everything I need to mockup the rack/diff and LCA positioning.

https://farm8.staticflickr.com/7865/46556151334_a065c11571_c.jpg ('https://flic.kr/p/2dW1rNo')

Updating the steering rack in the model. Looking good thus far. My initial measurements were fairly accurate. Looks like I can use the GM tie-rod without any modifications.

There may be some interference between the rack bushings and the diff. Since I am attaching the rack from the opposite side, I can trim down the bushing if needed for more clearance. The hard lines are my major concern, as they run along the back. I will mock up the rack today possibly, to see how it fits against the diff. Its 20F currently, so my motivation is low.

I dream of a heated/cooled garage with 11ft door...

After spending some quality time with the steering rack, and doing some rough FEA and math on the rack end spacers, I don't think they are a good option. On the PS side the offset spacer would be okay, as there is a beefy bushing, but on the DS there is just the pinion and preload spacer. My math puts the racks power assist at ~750lbs. Assuming dynamic loading will be 2.5 times that creates 170ft-lbs of torque on the rack gear. The pinion just isn't made for that. I could make a support bushing, but I don't see it having OEM level reliability. Part of this is due to the offset. I had to go to 1" of offset due to the larger 18mm thread GM used (there is a grease bore down the middle).

So I am stuck with whatever ackerman my rack placement allows. The good news is with the GM LCA angle, my ackerman is 60% at full lock. 100% ackerman would be 5.8 degrees, and I am at 3.5 degrees. Not ideal, but will be tolerable.

The MB rack is a bit narrower than ideal for bump steer. So I will still be using a rack-end spacer (around 1.5-2") but without the offset. This will allow using the GM tie rods. I will need to source a boot for the rack ends though. I might be able to modify the MB boots and machine a collar into the spacer. Shouldn't be hard.

The MB rack with MB tie rods has 6.5" of travel. I don't think the outer CVs will tolerate more than 6", but I will check before I make a limiting spacer. The GM tie rods are pretty thin, MBs are 5mm thicker (they are a bit longer).

I have the bump stop aligned pretty close as well.

I will likely get the diff and rack mocked up this week. If everything goes to plan, I can move on to the rack mounts.

The fox 2.0 5" travel units are looking pretty good. The will allow 8" of wheel travel, and should be up to medium duty service. There are some cheaper double tube coilovers, such as the DS701 etc, which could be used by the budget conscious. I would love fox 2.5s but perfect can be the enemy of good. If I need to rebuild the shocks every 30-40k miles, I think thats an acceptable trade off. I have beat the crap out of my current set of fox 2.0s, currently at 60k miles. Other than a bit of oil seep, at one, and a few failed bushings, they still work great.

One issue is that the 5" travel unit is only available in 5/8" shaft. Am I going to regret the 5/8" vs 7/8" shaft? The shock is only 17" long or so.

When it warms up I will pull measure the MB wheel speed sensors. If they will fit on the diff flanges, I will work up some tone wheels. Either weld on, or bolt on. Then I can move on to brake fittings/lines, etc.

Midwestdrifter
03-05-2019, 08:58 PM
Did a quick model with 245/75R16s. Clearance looks good. With 6" of rack travel, I may have some light rubbing at full lock and full droop. This is with a ~40mm ET wheel. Track width would be ~67". I think the GM factory wheel is ~ET25.

Midwestdrifter
03-05-2019, 08:58 PM
The sun came out for a bit, so I got to hacking on the Diff and rack. The rack will fit where I need it to go. One of the bushings/bosses needs trimmed about 0.5". The cylinder lines don't clear around the input shaft. So either new lines need flared/bent, or the existing lines need a significant tweak. I may see if I can source some rubber lines with elbow fittings? These look like brake line with a DIN flare, and metric nuts. Should be easy enough to source some copper/nickle tubing and flare tool.

I am still trying to dial in my bumpsteer. The last round of changes screwed it up (almost 1.5 deg in bump).

https://farm8.staticflickr.com/7907/47292300421_0669b8f8a4_c.jpg (https://flic.kr/p/2f44ph2)

https://farm8.staticflickr.com/7828/40327696193_79c4362a6f_c.jpg (https://flic.kr/p/24rBZ5M)

https://farm8.staticflickr.com/7849/46569104634_849abba116_c.jpg (https://flic.kr/p/2dX9Qn9)

https://farm8.staticflickr.com/7820/33416694638_994d40878a_c.jpg (https://flic.kr/p/SUVi6y)

https://farm8.staticflickr.com/7873/47292303691_55aac95b45_c.jpg (https://flic.kr/p/2f44qfp)

Midwestdrifter
03-07-2019, 11:25 PM
Contorted my arms into the engine bay, and took some measurements of the rack input shaft. Its miles better than the E series engine bays, but still lots of crap in the way. Turns out I have more clearance than I thought. The rack is now rotated back about 20 degrees from its factory orientation. So I get a bonus 3/8" of clearance at the diff! The original lines may even clear, which is even better. Some of it depends on what angle I need the pinion at. It may need to come up another 1-2 degrees to line up with the Tcase.

The risks of working with rough models, and measuring on your back, are translation errors. In this case I forgot to include the offset of my skid plate (used as a reference from the LCA pivot). It is really hard to get good measurements of the oil pan installed. Even worse with a skid plate!

Just a little bit of interference there. So the diff needs to come down. I need to triple check my measurements before I do all that work though. I can drop the diff a bit, and then lower the entire subframe some. I am trying to avoid the bro-dozer lift. Currently its about ~2" from stock, but that will need to increase some. Should be a pretty easy set of changes, assuming I didn't screw up and use the wrong references for my sketches...

AdrianD
03-08-2019, 11:37 AM
I'm happy to see the coilover instead of the torsion bar, love the progress of the design.

Ed463
03-10-2019, 07:26 PM
I've just stumbled on this thread, love it!!
Can't wait to see more progress.

Midwestdrifter
03-12-2019, 06:43 PM
I'm happy to see the coilover instead of the torsion bar, love the progress of the design.

Me too! I think the coilover is going to improve the ride quite a bit, plus shave a fair bit of weight as well.

I've just stumbled on this thread, love it!!
Can't wait to see more progress.

Thanks, I would love to tear apart my van today, but my bank account needs replenished, and high paying jobs can be tough to find, with wages stagnant in the USA since the 80s...

Back to the design;

Increasing the ride height was fairly painless. Added an inch to the subframe height, dropping everything down. So about 2.5" taller than stock now.


A lot depends on pinion angle and the draft angle on the casting. Pretty impossible to measure in-situ currently. Worst case I need to do a bit of clearance grinding on the Diff. I could shift the diff to the DS by 3/8". I may need CV spacers anyways, so that would be pretty simple to work out.

Midwestdrifter
03-14-2019, 04:28 PM
After consulting with some experts (off road fanatics really). I think a 2.5" diameter shock, and 3" ID spring would provide significant improvements in durability and ride. The larger shocks just need much lower pressures to dampen all that weight at a 1.7:1 damping ratio.

The 2.5" units are more expensive, but pay once cry once right? :lol:


The main issue with the 2.5 coilvovers is that they are 0.5" larger diameter and a bit longer. This means they interfere with the axle shaft and upper control arm. So to make them fit a riser plate needs fitted to raise the spring up enough to clear the shaft. The UCA needs to be trimmed, or a tubular high clearance arm fitted. I am still searching, but there should be tubular UCAs available somewhere.

Midwestdrifter
03-15-2019, 01:20 AM
Made a fox 2.5x6" coilover model (got half of it from some random one on the web). As mentioned the UCA does not even come close. I can shift the upper mount forwards a bit, which will help slightly, but a new UCA will be needed. I am hopeful I can find a solution that doesn't cost 600$+ for a pair of UCAs. Anyone with a 2011-2018 GM 2500 out there? I could use the dimensions of the UCA mounts, and the UCA overall length.

With a 1.4" lifted coil plate the axle shaft clears. There is still room for a 14" spring too. Though getting the shock compressed to mount will require a coil compressor I think.

Midwestdrifter
03-15-2019, 01:26 AM
It looks like Icon sells a 01-10 2500 UCA. $800 a pair... I guess it does have the high angle spherical. They may require larger wheels, which is undesirable.

The 2011-2018 GM 2500 UCA looks promising. Its much lower profile, and made of cast steel. Is the BJ the same taper/length? If not, can it be swapped for the earlier version? Assuming its roughly the same overall length/width, I can adapt my model to accommodate it. The late style looks to be narrower between the bushings. For 60$ it might be worth ordering one just to measure.

The early UCA, its formed/welded steel sheet. The early ball joint taper/shaft looks pretty similar to the later style. It looks like the later upper BJ is not replaceable?

OrioN
03-15-2019, 01:53 AM
:popcorn:

Midwestdrifter
03-21-2019, 10:24 PM
Made a fox 2.5x6" coilover model (got half of it from some random one on the web). As mentioned the UCA does not even come close. I can shift the upper mount forwards a bit, which will help slightly, but a new UCA will be needed. I am hopeful I can find a solution that doesn't cost 600$+ for a pair of UCAs. Anyone with a 2011-2018 GM 2500 out there? I could use the dimensions of the UCA mounts, and the UCA overall length.

With a 1.4" lifted coil plate the axle shaft clears. There is still room for a 14" spring too. Though getting the shock compressed to mount will require a coil compressor I think.

Midwestdrifter
03-21-2019, 10:25 PM
For the first time in many months I was able to set up my desktop. After working on my tiny (though heroic) laptop for so long, it was nearly orgasmic loading the model up. From 30 seconds to 3... Too bad it won't fit in the van. Though I doubt I could power it for long periods!

A bit of trimming and the factory Arm fits. Cutout is about 0.9" of the arm width with a light radius. There is room for a bit more meat on the upper side if needed. So if I can't find a decent high clearance one I can modify the stock unit with a doubler bracket welded to the top.

az7000'
03-23-2019, 04:48 PM
I like Chevy's too. This Ford solid front axle is pretty cool...

https://sprinter-source.com/forum/showthread.php?t=74592

Midwestdrifter
03-23-2019, 04:50 PM
The Ford running gear shorty sprinter Sinka is pretty cool. I would rock that. I discarded the idea of a solid front axle early on. Simply becuase it would require a significant life (6" or more) to get decent travel out of the front. And that is the major reason to go solid axle on the front, mega travel.

Midwestdrifter
03-26-2019, 02:28 AM
Put the diff on the jig table. Ran the CVs and BJs through the range. The boots don't like it, but the outer CVs will do 50 degrees. That is full lock and bump. Despite widening the suspension from stock, the inner CVs appear to have enough plunge. If its marginal, I will just add a spacer. Several folks make them, so shouldn't be an issue.

https://farm8.staticflickr.com/7807/46551917905_4de4ede546_c.jpg ('https://flic.kr/p/2dVCKme')


https://farm8.staticflickr.com/7895/33590638378_f9faf2ff4d_c.jpg ('https://flic.kr/p/TbhNvy')

https://farm8.staticflickr.com/7817/46551918345_a6940d2607_c.jpg ('https://flic.kr/p/2dVCKtP')


https://farm8.staticflickr.com/7912/40501095123_8bc4f3b395_c.jpg ('https://flic.kr/p/24GWGxv')

https://farm8.staticflickr.com/7861/47414260932_420e93fb9d_c.jpg ('https://flic.kr/p/2feQtTs')

https://farm8.staticflickr.com/7835/47414260682_589492b217_c.jpg ('https://flic.kr/p/2feQtP9')

Midwestdrifter
04-12-2019, 09:06 PM
I am a bit stalled on the subframe until I tear my van apart a bit. So I am digging into the low range fix.

I found this example of a CANbus bridge using the arduino Due hardware.
https://copperhilltech.com/blog/can-bus-bridge-cantocan-application-with-arduino-due/


The author kindly provides a sample sketch (attached zip). I am a rank amateur at arduino coding (and C in general). But I think the code base can be adapted to what I need to do. At about 90$, its not terribly expensive, and has lots of functionality if I need other functions.

User owner indicates that I need to modify CAN frames 0x200 for front wheels, and 0x208 for the rear wheels. The frame ID is 11 bits. The wheel speeds are stored as 16 bit values. Left wheels are in data bytes [4]..[5], and right is in [6]..[7] I don't know how the values are represented (RPM?, Pulses per second?). It doesn't matter much really. I just need to get the endian-ness right, and divide by 2.73.

So I need the program to match the frame ID with a table. If in low range, and the ID matches hex 200 or 208, modify bytes 4-7. All others are re-transmitted unmodified.

Midwestdrifter
04-14-2019, 05:26 PM
Digging into the code a bit, here is the relevant main loop. I have started annotating and modifying it for this application. Essentially it reads the CAN mailboxes on both CAN segments. If the messages ID matches, and low range is on, the bytes are modified and transmitted. Otherwise they are just transmitted unchanged. I still need to write the code to perform the speed division, and modify the Data array. I am not sure what the best way to modify the bytes in question. They are probably unsigned 16bit integers, but I haven't determined the endianness, either of the array, or the frame itself. Only 4 possible combinations, might be easier just to do a trial and error approach...

void loop()
{
// Declarations
byte cPort, cTxPort;
long lMsgID;
bool bExtendedFormat;
byte cData[8];
byte cDataLen;
int lowrange;

// Start timer for LED indicators
TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);

while(1) // Endless loop
{
// Control LED status according to CAN traffic
LEDControl();

//Read low range switch and assign to lowrange varaible
lowrange=digitalread(LRSW);

// Check for received CAN messages
for(cPort = 0; cPort <= 1; cPort++)
{

if(canRx(cPort, &lMsgID, &bExtendedFormat, &cData[0], &cDataLen) == CAN_OK)
{
// Scan through the mapping list, If frame matches ID and lowrange is high.
for(int nIndex = 0; nIndex < nMappingEntries; nIndex++)
{
if(lMsgID == CAN_DataMapping[nIndex].lReceivingMsgID
// Removed matching for source CAN port
// && cPort == CAN_DataMapping[nIndex].cReceivingPort
&& lowrange == 1
)
{
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;
//Wheel speed conversion

// Transmit Frame, print error message if CAN_ERROR is returned
if(canTx(cTxPort, CAN_DataMapping[nIndex].lTransmittedMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)
Serial.println("Transmision Error.");


}
//Transmit Frames If low range is not active, or for non-matching frames
else {
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;
(canTx(cTxPort, lMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)
Serial.println("Transmision Error.");
}// end if else

}// end for

}// end if

}// end for

}// end while

}// end loop

Midwestdrifter
04-17-2019, 02:06 AM
Some tangentially related news. My wife and I just accepted job offers in Charlotte NC, starting immediately. So we will be making the move out that way in the near future. Looks like that will be our home for a few years. The good news is that I will hopefully have a garage at some point. Though if we get stuck in an apartment, that may be for several months.





On the CANbus code front, I am about 90% done with a draft program. This one should pass all frames between the segments. For 0x200 and 0x208 it will read the relevant bytes into integer variables and divide by 2.73 (when low range pin is high). For frame 0x200 there is an average speed for the front wheels in bytes 2-3. I am not sure if this is used by the TCM or not. I don't think the rear wheel frame (0x208) has an average value in the frame. I won't know until I do some testing, and capture some of the relevant frames. The program is setup to print relevant values to the serial line, so I can monitor via a computer.



Other tidbits; the values from the frames are little endian (lowest value byte first). So is the Due controller I am writing code for.





void loop()

{

// Declarations

byte cPort, cTxPort;

long lMsgID;

bool bExtendedFormat;

byte cData[8];

byte bData[4];

byte cDataLen;

int lowrange;



// Start timer for LED indicators

TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);



while(1) // Endless loop

{

// Control LED status according to CAN traffic

LEDControl();



//Read low range switch and assign to lowrange varaible

lowrange=digitalread(LRSW);



// Check for received CAN messages

for(cPort = 0; cPort <= 1; cPort++)

{



if(canRx(cPort, &lMsgID, &bExtendedFormat, &cData[0], &cDataLen) == CAN_OK)

{

// Scan through the mapping list, If frame matches ID and lowrange is high.

for(int nIndex = 0; nIndex < nMappingEntries; nIndex++)

{

if(lMsgID == CAN_DataMapping[nIndex].lReceivingMsgID

// Removed matching for source CAN port

// && cPort == CAN_DataMapping[nIndex].cReceivingPort

&& lowrange == 1

)

{

//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.

cTxPort = 0;

if(cPort == 0) cTxPort = 1;



//Initialize wheel speed int to zero

short wSpeedL = 0;

short wSpeedR = 0;

short wSpeedA = 0;



//copy speed data bytes to working array from CAN data array

bData[0] = cData[4];

bData[1] = cData[5];

bData[2] = cData[6];

bData[3] = cData[7];



//Set wSpeed to array data

wSpeedL = (wSpeedL << 8) + bData[0];

wSpeedL = (wSpeedL << 8) + bData[1];

wSpeedR = (wSpeedR << 8) + bData[2];

wSpeedR = (wSpeedR << 8) + bData[3];



//print data for debug

Serial.print("wSpeedL raw =");

Serial.println(wSpeedL);

Serial.print("wSpeedR raw =");

Serial.println(wSpeedR);



//For Front wheels, frame 0x200, adjust front wheel average speed.

if (lMsgID == 0x200)

{

// copy speed data to wSpeedA

wSpeedA = (wSpeedA << 8) + cData[2];

wSpeedA = (wSpeedA << 8) + cData[3];



//debug printing

Serial.print("Front average speed CAN Raw, cData[2]..[3] =");

Serial.print(cdata[2], HEX);

Serial.println(cdata[3], HEX);

Serial.print("wSpeedA = ");

Serial.println(wSpeedA);



//divide average speed

wSpeedA = (wSpeedL/2.73);



Serial.print("wSpeedA divided = ");

Serial.println(wSpeedA);



//Copy revised speed to data array

void memcpy (cData[2], (byte*)&(wSpeedA),sizeof(wSpeedA));



Serial.print("Front average speed Converted Raw, cData[2]..[3] =");

Serial.print(cdata[2], HEX);

Serial.println(cdata[3], HEX);

} //end if



//Divide Wheel speeds by 2.73

wSpeedL = (wSpeedL/2.73);

wSpeedR = (wSpeedR/2.73);



//print data for debug

for (int mIndex=4; mIndex <= 7; mIndex++)

{

Serial.println("cData [4]..[7]");

Serial.print(mIndex);

Serial.print("-");

Serial.println(cdata[mIndex], HEX);

}//end for loop



//Copy wSpeedL and wSpeedR to working array, Note offset for start byte. Assumes both CAN frame and chip are little endian

void memcpy (bData[0], (byte*)&(wSpeedL),sizeof(wSpeedL));

void memcpy (bData[2], (byte*)&(wSpeedR),sizeof(wSpeedR));



//Print working array contents

for (int mIndex=0; mIndex <= 3; mIndex++)

{

Serial.println("bData[0]..[3]");

Serial.print(mIndex);

Serial.print("-");

Serial.println(bdata[mIndex], HEX);

}//end for loop





//Copy bData to data array

cData[4] = bData[0];

cData[5] = bData[1];

cData[6] = bData[2];

cData[7] = bData[3];





// Transmit Frame, print error message if CAN_ERROR is returned

if(canTx(cTxPort, CAN_DataMapping[nIndex].lTransmittedMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)

Serial.println("Transmision Error.");





}



//Transmit Frames If low range is not active, or for non-matching frames

else {

//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.

cTxPort = 0;

if(cPort == 0) cTxPort = 1;

(canTx(cTxPort, lMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)

Serial.println("Transmision Error.");

}// end if else



}// end for



}// end if



}// end for



}// end while



}// end loop

AdrianD
04-18-2019, 02:34 PM
I haven't gone through the code but I suggest getting some data first from the CAN BUS. There's a guy in Estonia who builds such a board for the Jeep + OM612 + NAG1 application, in order to change the axle ratios.

This will also help if you use low-range, you will need to use a GPIO to read the transfer case switch and you're golden.

Midwestdrifter
04-30-2019, 06:45 PM
An engineering contact volunteered his time (thanks M!). He wrote a arduino program that reads input pulses on two channels, and outputs a square wave (digital output) on two lines. Frequency is converted at will. I will likely need some tweaking of various values. It may need a bit of logic to appropriately handle wheel lock up. I am confident the microprocessor is fast enough to produce accurate results though. The code is written below. This would allow me to use the GM WSS, and feed the result into the ESP/ABS module.



Since the WSS outputs a variable AC voltage (between 2-9V?). I need a filter circuit for the input. Both to protect the controller against voltage excursions, and to convert the sine wave to a digital square waveform. My thoughts are to use a schmitt trigger circuit. Essentially this is a crossing zero comparator. When the sine wave crosses zero, the OP-amp goes high, when it goes below zero, it goes low. The circuit below uses a voltage divider, noise and peak current suppression capacitor, etc. I will need to adjust the capacitor and resister values, but it should suppress ambient RF noise and produce a nice clean square wave.



https://electronics.stackexchange.com/questions/163253/sine-wave-to-square-wave-schmitt-trigger







For the output to the ESP/ABS module, I need to do some testing to see what works. It would be great if the unit accepts a 0-5V square wave (no negative excursions). If not, I am thinking of using a 9-12V supply chip and center tap the output ground, and have the ardino switch a transistor to drive the output to plus/minus 4-6V. This will be a square wave of course. If the controller still doesn't like that, I will have to simulate an actual sine wave. I doubt that will be necessary though.







// Arudino code for Sprinter Wheel Sensor frequency conversion



// Serial output constants

const bool SERIAL_OUTPUT = true; // set to true to send data out serial line

const bool SERIAL_DIAGNOSE = false; // set to true to send back what was recieved

const long SERIAL_REPORT = 1e6; // report over serial every second



// Conversion constants

const bool ENABLE_CONVERSION = false; // Set to true to turn on conversion

const float freq_to_mph = 30.0 * 3.1416 / 55 / 12 / 5280 * 60 * 60; // Hz to mph conversion; assumes 30in wheel diameter, 55 ticks per revolution

const float freq_to_rpm = 1.0 / 55 * 60; // Hz to rpm conversion; assumes 55 ticks per revolution

const float stall_time = 1e6; // If wheel is stopped for 1 second, force speed to 0

float time_conversion = 55.0 / 44; // converts from real sensor with 55 ticks to 44 ticks



// Input/Output pins

const int INPUT_PIN_L = 2; // left wheel input

const int INPUT_PIN_R = 3; // right wheel input

const int OUTPUT_PIN_L = 4; // left wheel output

const int OUTPUT_PIN_R = 5; // right wheel output



// Time variables

unsigned long start_time_left = micros(); // For output cycle

unsigned long start_time_right = micros();

unsigned long last_time_left = micros(); // For input cycle

unsigned long last_time_right = micros();

unsigned long serial_time = micros();

unsigned long current_time = micros();



// Main variables

float t_out_left = 1e6; // period, in microseconds

float t_out_right = 1e6;

float t_in_left = 1e6; // period, in microseconds

float t_in_right = 1e6;

bool high_left = false;

bool high_right = false;

float avg_speed = 0;





// Initial set-up code

void setup() {



// Setup Pin Modes

pinMode(INPUT_PIN_L, INPUT_PULLUP);

pinMode(INPUT_PIN_R, INPUT_PULLUP);

pinMode(OUTPUT_PIN_L, OUTPUT);

pinMode(OUTPUT_PIN_R, OUTPUT);



// Setup Interrupts

//attachInterrupt(INPUT_PIN_L, ISR_L, RISING);

//attachInterrupt(INPUT_PIN_R, ISR_R, RISING);

attachInterrupt(digitalPinToInterrupt(INPUT_PIN_L) , ISR_L, RISING);

attachInterrupt(digitalPinToInterrupt(INPUT_PIN_R) , ISR_R, RISING);



// Begin Serial

Serial.begin(115200);



// Setup variables

if (! ENABLE_CONVERSION) time_conversion = 1;

start_time_left = micros();

start_time_right = micros();

serial_time = micros();



if (SERIAL_OUTPUT) {

if (ENABLE_CONVERSION) Serial.println("Speed Conversion is ON");



Serial.print("Time (ms)"); // Overall Time

Serial.print("\t");

Serial.print("Left Wheel Input (rpm)"); // Speed from left wheel sensor

Serial.print("\t");

Serial.print("Right Wheel Input (rpm)"); // Speed from right wheel sensor

Serial.print("\t");

Serial.print("Left Wheel Output (mph)"); // Speed output to car

Serial.print("\t");

Serial.println("Right Wheel Output (mph)"); // Speed output to car

}

}





void loop() {



// update times

current_time = micros();

if (current_time - start_time_left > t_out_left) {

t_out_left = t_in_left * time_conversion;

if (current_time - last_time_left > stall_time) t_out_left = 1e9;

start_time_left = current_time;

}

if (current_time - start_time_right > t_out_right) {

t_out_right = t_in_right * time_conversion;

if (current_time - last_time_right > stall_time) t_out_right = 1e9;

start_time_right = current_time;

}



// write output waveform

if (current_time - start_time_left < t_out_left/2) { // write HIGH during 1st half of cycle

if (! high_left) {

digitalWrite(OUTPUT_PIN_L, HIGH);

high_left = true;

}

}

else { // write LOW

if (high_left) {

digitalWrite(OUTPUT_PIN_L, LOW);

high_left = false;

}

}

if (current_time - start_time_right < t_out_right/2) { // write HIGH during 1st half of cycle

if (! high_right) {

digitalWrite(OUTPUT_PIN_R, HIGH);

high_right = true;

}

}

else { // write LOW

if (high_right) {

digitalWrite(OUTPUT_PIN_R, LOW);

high_right = false;

}

}



// write to serial

if (SERIAL_OUTPUT && current_time - serial_time > SERIAL_REPORT) {



Serial.print(millis()); // Overall Time

Serial.print("\t");

Serial.print(1e6 / t_in_left * freq_to_rpm); // Speed from left wheel sensor

Serial.print("\t");

Serial.print(1e6 / t_in_right * freq_to_rpm); // Speed from right wheel sensor

Serial.print("\t");

Serial.print(1e6 / t_out_left * freq_to_mph); // Speed output to car

Serial.print("\t");

Serial.println(1e6 / t_out_right * freq_to_mph); // Speed output to car



serial_time = current_time;

}

}

// end loop



// Interrupt Routines - runs once on each input cycle (when encoder rises)

void ISR_L() {

// Update times

current_time = micros();

t_in_left = current_time - last_time_left;

last_time_left = current_time;

}



void ISR_R() {

// Update times

current_time = micros();

t_in_right = current_time - last_time_right;

last_time_right = current_time;

}

Midwestdrifter
05-23-2019, 10:55 PM
Long time no post. We are moved in and started working, so my time is limited again. As a plus I have income, so its a mixed bag. I need to unpack my garage, and get some work tables, a new welder, bench vise, grinder, etc...



I ordered an arduino due, and I will get that setup for the van. Should be easy enough to do some testing.



I need the van to be operational until I get a vehicle for my wife. So until then I am holding off of tearing it down. First step is to loosen and lower the subframe about half an inch, that will let me measure the mounting bolts and engine mount location. If everything looks good, I will order shocks, springs, and new GM wear parts. If those all match my model, I will do final tweaks, generate the DXFs, and send for fabrication. An aggressive timeline would be about 8 weeks. Likely 12.

calbiker
05-24-2019, 12:27 AM
micros() is unsigned long (~ 4E9 counts)

micros will overflow in 4E9/1E6 = 4000 seconds = 67 minutes

I had that problem with a data logger when using micros()

Will millis() work?


void ISR_R() {

// Update times

current_time = micros();

t_in_right = current_time - last_time_right;

last_time_right = current_time;

}

Midwestdrifter
05-24-2019, 12:36 AM
I would guess probably not? I need to sit down and do the math. Peak frequencies would be in the 1khz range? So milliseconds may have enough resolution. I can test it either way.

Worst case I can add a if statement to restart the loop when it rolls to zero. The waveform would have a brief interruption, but I doubt it would cause issues.

Midwestdrifter
05-24-2019, 02:12 AM
Looking at the microsecond rollover, because both are unsigned longs, the subtraction should still yield the correct difference values. I need to go through the program and evaluate the comparison expressions to see if they will all produce good results just after a rollover/

http://www.utopiamechanicus.com/article/handling-arduino-microsecond-overflow/

owner
05-24-2019, 05:03 AM
You can change your code to be a lot faster...

Instead of doing floating point division (which is basically the slowest of all operations you could do):
wSpeedL = (wSpeedL/2.73);

Take the scaled inverse of 2.73 ((1/2.73)*10000) = 3633 and do it with integers:
wSpeedL = ((wSpeedL * 3633)/10000);

This will be so much faster its not even funny.

You can even get rid of the divide by using a binary scale factor like 4096.
So ((1/2.73)*4096) = 1500 so it becomes:
wSpeedL = ((wSpeedL * 1500)>>12);

That will be even yet still faster.

calbiker
05-24-2019, 06:38 PM
I'm not sure if you access micros() several times within one loop, and then compare values. If that's the case, when you get an overflow between accessing micros(), you will have a problem.

Micros overflows ~ every 70 minutes. In my case, a problem occurred 4 hours into operation.

Looking at the microsecond rollover, because both are unsigned longs, the subtraction should still yield the correct difference values. I need to go through the program and evaluate the comparison expressions to see if they will all produce good results just after a rollover/

http://www.utopiamechanicus.com/article/handling-arduino-microsecond-overflow/

owner
05-25-2019, 12:44 AM
If getting one crap sample every 4 hours is going to be a problem, You would just need to test to see if the second time is greater than the first. If it isnt then do a special case to work out the time delta using the rolledover 2nd time. ie timeDelta = MAX_INT - oldTime + newTime.

Midwestdrifter
05-25-2019, 06:51 PM
Thanks for the help Guys. I went through the low-range program and made a few changes. I added a IF/else statement with counter so that the Serial Print only happens every second. I also changed streamlined the division operation as suggested. The Due has plenty of capacity for this application, but its just good practice to improve efficiency where possible. my IDE takes issue with the memcpy function, but we will see what happens when I go to debug.


As for the micros rollover on the front wheels, Given the rate the program operates, and the built in filtering the ESP module uses, I don't see any issue with the 1-2 bad samples at 400-900hz. Its not likely to even register with the ESP module. If it does, I will add a line to adjust the timing intervals after a rollover.


//Required Libraries
#include "string.h"
#include "Arduino.h"

//
//Set debug printing
bool SERIAL_DEBUG = true;



// CAN Layer functions
// -----------------------------------------------------------------------------------------------
#include "DueCANLayer.h"
extern byte canInit(byte cPort, long lBaudRate, int nTxMailboxes);
extern byte canTx(byte cPort, long lMsgID, bool bExtendedFormat, byte* cData, byte cDataLen);
extern byte canRx(byte cPort, long* lMsgID, bool* bExtendedFormat, byte* cData, byte* cDataLen);

// Timer functions
// -----------------------------------------------------------------------------------------------
#include "TimerControl.h"
extern void TimerInit(void);
extern void TimerControl(void);
extern void TimerStart(struct Timer* pTimer, int nCount);
extern void TimerReset(struct Timer* pTimer);
extern struct Timer pTimer[];


// CAN Bus Data Mapping
// -----------------------------------------------------------------------------------------------
struct Mapping
{
byte cReceivingPort; // 0/1
long lReceivingMsgID;
long lTransmittedMsgID;
};

//recieving port and trasmitted ID function retained for future usage
struct Mapping CAN_DataMapping[] = {
// cReceivingPort, lReceivingMsgID, lTransmittedMsgID
0, 0x208, 0x208,
0, 0x200, 0x200 // End of Table
};

int nMappingEntries = 0; // Will be determined in setup()

// Internal functions
// -----------------------------------------------------------------------------------------------
void LEDControl(void);

// Module variables
// -----------------------------------------------------------------------------------------------
int TimerActivity_CAN0 = 0;
int TimerActivity_CAN1 = 0;

int LED1 = 14;
int LED2 = 15;
//Low Range Switch Pin Number (TBD)
int LRSW = X;

int nTxMailboxes = 3; // Equal portion between transmission and reception

void setup()
{
// Set the serial interface baud rate
Serial.begin(115200);

// Initialzie the timer control; also resets all timers
TimerInit();

// Determine simulation entries
nMappingEntries = 0;
while(1)
{
if(CAN_DataMapping[nMappingEntries].cReceivingPort == 0
|| CAN_DataMapping[nMappingEntries].cReceivingPort == 1)
nMappingEntries++;
else
break;
}

// Initialize the outputs for the LEDs
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LRSW, INPUT);
// Initialize Low Range Input pin

// Initialize both CAN controllers
if(canInit(0, CAN_BPS_500K, nTxMailboxes) == CAN_OK)
Serial.print("CAN0: Initialized Successfully.\n\r");
else
Serial.print("CAN0: Initialization Failed.\n\r");

if(canInit(1, CAN_BPS_500K, nTxMailboxes) == CAN_OK)
Serial.print("CAN1: Initialized Successfully.\n\r");
else
Serial.print("CAN1: Initialization Failed.\n\r");


}// end setup

void loop()
{
// Declarations
byte cPort, cTxPort;
long lMsgID;
bool bExtendedFormat;
byte cData[8];
byte bData[4];
byte cDataLen;
int lowrange;
unsigned short wSpeedL;
unsigned short wSpeedR;
unsigned short wSpeedA;
unsigned long previousMillis = 0;
unsigned long interval = 1000;
//Serial printing interval
bool SERIAL_OUTPUT= false;

// Start timer for LED indicators
TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);

while(1) // Endless loop
{
// Control LED status according to CAN traffic
LEDControl();

//Read low range switch and assign to lowrange varaible
lowrange=digitalRead(LRSW);

//Serial Print Interval

if ( SERIAL_DEBUG=1)
{
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval)
{
// save the last time Serial Printing Occured
previousMillis = currentMillis;
// Set Print to serial
SERIAL_OUTPUT = true;

}
else (SERIAL_OUTPUT = false);

}
// Check for received CAN messages
for(cPort = 0; cPort <= 1; cPort++)
{

if(canRx(cPort, &lMsgID, &bExtendedFormat, &cData[0], &cDataLen) == CAN_OK)
{
// Scan through the mapping list, If frame matches ID and lowrange is high.
for(int nIndex = 0; nIndex < nMappingEntries; nIndex++)
{
if(lMsgID == CAN_DataMapping[nIndex].lReceivingMsgID
// Removed matching for source CAN port
// && cPort == CAN_DataMapping[nIndex].cReceivingPort
&& lowrange == 1
)
{
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;

//Initialize wheel speed int to zero
wSpeedL = 0;
wSpeedR = 0;
wSpeedA = 0;

//copy speed data bytes to working array from CAN data array
bData[0] = cData[4];
bData[1] = cData[5];
bData[2] = cData[6];
bData[3] = cData[7];

//Set wSpeed to array data
wSpeedL = (wSpeedL << 8) + bData[0];
wSpeedL = (wSpeedL << 8) + bData[1];
wSpeedR = (wSpeedR << 8) + bData[2];
wSpeedR = (wSpeedR << 8) + bData[3];

//print data for debug
if (SERIAL_OUTPUT)
{
Serial.print("wSpeedL raw =");
Serial.println(wSpeedL);
Serial.print("wSpeedR raw =");
Serial.println(wSpeedR);
}

//For Front wheels, frame 0x200, adjust front wheel average speed.
if (lMsgID == 0x200)
{
// copy speed data to wSpeedA
wSpeedA = (wSpeedA << 8) + cData[2];
wSpeedA = (wSpeedA << 8) + cData[3];

//debug printing
if (SERIAL_OUTPUT)
{
Serial.print("Front average speed CAN Raw, cData[2]..[3] =");
Serial.print(cData[2], HEX);
Serial.println(cData[3], HEX);
Serial.print("wSpeedA = ");
Serial.println(wSpeedA);
}
//divide average speed by 2.73 using binary scale factor, ((1/2.73)*4096) = 1500
wSpeedA = ((wSpeedA * 1500)>>12);

if (SERIAL_OUTPUT)
{
Serial.print("wSpeedA divided = ");
Serial.println(wSpeedA);
}//end If

//Copy revised speed to data array
void memcpy (cData[2], (byte*)&(wSpeedA), sizeof(wSpeedA));

if (SERIAL_OUTPUT)
{
Serial.print("Front average speed Converted Raw, cData[2]..[3] =");
Serial.print(cData[2], HEX);
Serial.println(cData[3], HEX);
}
} //end if

//Divide Wheel speeds by 2.73 using binary scale factor, ((1/2.73)*4096) = 1500
wSpeedL = ((wSpeedL * 1500)>>12);
wSpeedR = ((wSpeedR * 1500)>>12);

//print data for debug
if (SERIAL_OUTPUT)
{
for (int mIndex=4; mIndex <= 7; mIndex++)
{
Serial.println("cData [4]..[7]");
Serial.print(mIndex);
Serial.print("-");
Serial.println(cData[mIndex], HEX);
}//end for loop
} //end If

//Copy wSpeedL and wSpeedR to working array, Note offset for start byte. Assumes both CAN frame and chip are little endian
void memcpy( bData[0], (byte*)&(wSpeedL),sizeof(wSpeedL));
void memcpy( bData[2], (byte*)&(wSpeedR),sizeof(wSpeedR));


//Print working array contents
if (SERIAL_OUTPUT)
{
for (int mIndex=0; mIndex <= 3; mIndex++)
{
Serial.println("bData[0]..[3]");
Serial.print(mIndex);
Serial.print("-");
Serial.println(bData[mIndex], HEX);
}//end for loop
}//end If

//Copy bData to data array
cData[4] = bData[0];
cData[5] = bData[1];
cData[6] = bData[2];
cData[7] = bData[3];


// Transmit Frame, print error message if CAN_ERROR is returned
if(canTx(cTxPort, CAN_DataMapping[nIndex].lTransmittedMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)
Serial.println("Transmision Error.");


}

//Transmit Frames If low range is not active, or for non-matching frames
else
{
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;

if (canTx(cTxPort, lMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR) Serial.println("Transmision Error.");
}// end if else

}// end for

}// end if

}// end for

}// end while

}// end loop

// ------------------------------------------------------------------------
// LED Data Traffic
// ------------------------------------------------------------------------
// Note: CAN0 --> LED1
// CAN1 --> LED2
//
void LEDControl(void)
{
if(pTimerLEDs.bExpired == true)
{
// Restart the timer
TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);

// Check for activity on CAN0
if(TimerActivity_CAN0 > 0)
{
TimerActivity_CAN0--;
digitalWrite(LED1, HIGH);
}// end if
else
digitalWrite(LED1, LOW);

// Check for activity on CAN1
if(TimerActivity_CAN1 > 0)
{
TimerActivity_CAN1--;
digitalWrite(LED2, HIGH);
}// end if
else
digitalWrite(LED2, LOW);

}// end if

}// end LEDControl

calbiker
05-26-2019, 04:25 PM
This is all new to me & trying to understand it. Does the WSS (wheel sensor) output a variable frequency proportional to wheel rpm? If that's the case, the frequency can get very small, like 1 Hz?

I believe the circuit shown is designed to operate at 1 kHz. It uses a 10 uF capacitor. At any given frequency the capacitor acts as a resistor, given by:

Xc = 1 / (2*PI*f*C)

At 1 kHz, the capacitor resistance is small: 16 ohm.

But at 1 Hz, resistance is very large: 16 kohm. Your circuit may not work. You did mention the need to "tweek" the cap. A 100 uf cap will result in 1.6 kohm resistance. That's still substantial.

As I understand it, the Schmitt trigger signal goes into the Sprinter ESP/ABS module. How do you get the front wheels and back wheels to turn at same rpm? Is the front and back wheel gearing 100% accurate?



Since the WSS outputs a variable AC voltage (between 2-9V?). I need a filter circuit for the input. Both to protect the controller against voltage excursions, and to convert the sine wave to a digital square waveform. My thoughts are to use a schmitt trigger circuit. Essentially this is a crossing zero comparator. When the sine wave crosses zero, the OP-amp goes high, when it goes below zero, it goes low. The circuit below uses a voltage divider, noise and peak current suppression capacitor, etc. I will need to adjust the capacitor and resister values, but it should suppress ambient RF noise and produce a nice clean square wave.



https://electronics.stackexchange.com/questions/163253/sine-wave-to-square-wave-schmitt-trigger


For the output to the ESP/ABS module, I need to do some testing to see what works. It would be great if the unit accepts a 0-5V square wave (no negative excursions). If not, I am thinking of using a 9-12V supply chip and center tap the output ground, and have the ardino switch a transistor to drive the output to plus/minus 4-6V. This will be a square wave of course. If the controller still doesn't like that, I will have to simulate an actual sine wave. I doubt that will be necessary though.

Midwestdrifter
05-26-2019, 04:37 PM
This is all new to me & trying to understand it. Does the WSS (wheel sensor) output a variable frequency proportional to wheel rpm? If that's the case, the frequency can get very small, like 1 Hz?

I believe the circuit shown is designed to operate at 1 kHz. It uses a 10 uF capacitor. At any given frequency the capacitor acts as a resistor, given by:

Xc = 1 / (2*PI*f*C)

At 1 kHz, the capacitor resistance is small: 16 ohm.

But at 1 Hz, resistance is very large: 16 kohm. Your circuit may not work. You did mention the need to "tweek" the cap. A 100 uf cap will result in 1.6 kohm resistance. That's still substantial.

As I understand it, the Schmitt trigger signal goes into the Sprinter ESP/ABS module. How do you get the front wheels and back wheels to turn at same rpm? Is the front and back wheel gearing 100% accurate?


The GM front tone wheels are 55 tooth, the sprinters are 44, so to use the GM tone wheels/sensors, I need to modify the pulse frequency by 1.25.

To do this I am looking at using an arduino to read the GM WSS output (via the schmit trigger). The trigger going high sets an interrupt. This triggers the program to record the time. Which each trigger interrupt the program evaluates how long the input pin has been high. This time is then adjusted, and the output pins are written high/low accordingly. With each cycle the program compares the high/low time for the inputs and outputs. Note that I did not author this program, a generous EE offered his time.

The sample rate will vary with program speed, but should be high enough to produce a reasonably stable output signal.

With 30" tires, the revs per mile is about 600. With 55 pules per rev, at 60MPH that is 600*55=33000 pules/min, or 550hz. At 5mph (the minimum that we need to read), its 45hz. So the range of input frequencies is ~45-750hz.

Now the output of the "black box" is where I am currently at. The arduinos digital pins can output +5V and 40mA. I need to experiment to see if the ESP/ABS module is okay with a 0 to +5V square wave. I will need a resister to simulate the WSS coil. I am not sure if I need ground isolation or not, as the ESP module will likely check for that.

If the ESP module is not okay with a 0-5V square wave, I will need to work something else out. Some Rs232 driver modules have built in caps which will allow a -5V to +5V output. Some reading indicates that the ESP module may need high voltages :idunno:.

calbiker
05-26-2019, 05:27 PM
Do you really require the capacitor? At 45 Hz, its resistance is 3.5 kohm.

The circuit you posted is designed to maintain ac signal integrity. No changes to the waveform. You should be able to reference the signal to ground and delete the cap.

edit:

This should be a better circuit for you. Don't know if you require optoisolator U2.

https://www.researchgate.net/publication/304661494/figure/fig1/AS:643297169133568@1530385405014/Wheel-speed-sensor-signal-conditioning-circuit.png

Midwestdrifter
05-26-2019, 06:37 PM
I haven't done any analog circuit design since university. I probably don't need the capacitor. The only real concern is to make sure the circuit can handle a bit of noise at low wheel speeds, as the voltage is low. The circuit you posted above appears to have parallel caps for this purpose.

calbiker
05-26-2019, 08:31 PM
The capacitor in the two designs have completely different purposes. The cap in the design you posted is actually a high pass filter. It will forward any noise that's on the line. If the noise is large enough, the schmitt trigger will switch states.

The other design has a second order RC low pass filter at its input. It filters any signals larger than 1 kHz. That's perfect, as you're not expecting frequencies above 550 Hz.

Midwestdrifter
05-26-2019, 10:24 PM
Great, thanks for the help. I have some parts on order, so I will add the OP-amps and caps to the list. I am going to try pushing a couple different waveforms to the ESP module, just to see what it does. If it reports wheel speeds over canbus, I will have found the winner.

After messing around with a couple different IDEs, I finally got my CAN Bridge Program to compile successfully. The memcpy function must be implemented oddly in the Arduino Due libraries...

Anyways, here is the updated code. I just switched to using the highbyte/lowbyte functions to assign the output array bytes to the correct values. Assuming there is no other mess-ups, I just need to run some data through the unit, and see what comes out of the serial console. I took an educated guess on the endianess, but I will need to confirm.


//Required Libraries

#include "Arduino.h"

//
//Set debug printing
bool SERIAL_DEBUG = true;



// CAN Layer functions
// -----------------------------------------------------------------------------------------------
#include "DueCANLayer.h"
extern byte canInit(byte cPort, long lBaudRate, int nTxMailboxes);
extern byte canTx(byte cPort, long lMsgID, bool bExtendedFormat, byte* cData, byte cDataLen);
extern byte canRx(byte cPort, long* lMsgID, bool* bExtendedFormat, byte* cData, byte* cDataLen);

// Timer functions
// -----------------------------------------------------------------------------------------------
#include "TimerControl.h"
extern void TimerInit(void);
extern void TimerControl(void);
extern void TimerStart(struct Timer* pTimer, int nCount);
extern void TimerReset(struct Timer* pTimer);
extern struct Timer pTimer[];


// CAN Bus Data Mapping
// -----------------------------------------------------------------------------------------------
struct Mapping
{
byte cReceivingPort; // 0/1
long lReceivingMsgID;
long lTransmittedMsgID;
};

//recieving port and trasmitted ID function retained for future usage
struct Mapping CAN_DataMapping[] = {
// cReceivingPort, lReceivingMsgID, lTransmittedMsgID
0, 0x208, 0x208,
0, 0x200, 0x200 // End of Table
};

int nMappingEntries = 0; // Will be determined in setup()

// Internal functions
// -----------------------------------------------------------------------------------------------
void LEDControl(void);

// Module variables
// -----------------------------------------------------------------------------------------------
int TimerActivity_CAN0 = 0;
int TimerActivity_CAN1 = 0;

int LED1 = 14;
int LED2 = 15;
//Low Range Switch Pin Number (TBD)
int LRSW = 22;

int nTxMailboxes = 3; // Equal portion between transmission and reception

void setup()
{
// Set the serial interface baud rate
Serial.begin(115200);

// Initialzie the timer control; also resets all timers
TimerInit();

// Determine simulation entries
nMappingEntries = 0;
while(1)
{
if(CAN_DataMapping[nMappingEntries].cReceivingPort == 0
|| CAN_DataMapping[nMappingEntries].cReceivingPort == 1)
nMappingEntries++;
else
break;
}

// Initialize the outputs for the LEDs
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);

// Initialize Low Range Input pin
pinMode(LRSW, INPUT);
// Initialize Low Range Input pin

// Initialize both CAN controllers
if(canInit(0, CAN_BPS_500K, nTxMailboxes) == CAN_OK)
Serial.print("CAN0: Initialized Successfully.\n\r");
else
Serial.print("CAN0: Initialization Failed.\n\r");

if(canInit(1, CAN_BPS_500K, nTxMailboxes) == CAN_OK)
Serial.print("CAN1: Initialized Successfully.\n\r");
else
Serial.print("CAN1: Initialization Failed.\n\r");


}// end setup

void loop()
{
// Declarations
byte cPort, cTxPort;
long lMsgID;
bool bExtendedFormat;
byte cData[8];
byte bData[4];
byte cDataLen;
int lowrange;
unsigned short wSpeedL;
unsigned short wSpeedR;
unsigned short wSpeedA;
unsigned long previousMillis = 0;
unsigned long interval = 1000;
//Serial printing interval
bool SERIAL_OUTPUT= false;


// Start timer for LED indicators
TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);

while(1) // Endless loop
{
// Control LED status according to CAN traffic
LEDControl();

//Read low range switch and assign to lowrange varaible
lowrange=digitalRead(LRSW);

//Serial Print Interval

if (SERIAL_DEBUG)
{
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval)
{
// save the last time Serial Printing Occured
previousMillis = currentMillis;
// Set Print to serial
SERIAL_OUTPUT = true;

}
else (SERIAL_OUTPUT = false);

}
// Check for received CAN messages
for(cPort = 0; cPort <= 1; cPort++)
{

if(canRx(cPort, &lMsgID, &bExtendedFormat, &cData[0], &cDataLen) == CAN_OK)
{
// Scan through the mapping list, If frame matches ID and lowrange is high.
for(int nIndex = 0; nIndex < nMappingEntries; nIndex++)
{
if(lMsgID == CAN_DataMapping[nIndex].lReceivingMsgID
// Removed matching for source CAN port
// && cPort == CAN_DataMapping[nIndex].cReceivingPort
&& lowrange == 1
)
{
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;

//Initialize wheel speed int to zero
wSpeedL = 0;
wSpeedR = 0;
wSpeedA = 0;

//copy speed data bytes to working array from CAN data array
bData[0] = cData[4];
bData[1] = cData[5];
bData[2] = cData[6];
bData[3] = cData[7];

//Set wSpeed to array data
wSpeedL = (wSpeedL << 8) + bData[0];
wSpeedL = (wSpeedL << 8) + bData[1];
wSpeedR = (wSpeedR << 8) + bData[2];
wSpeedR = (wSpeedR << 8) + bData[3];

//print data for debug
if (SERIAL_OUTPUT)
{
Serial.print("wSpeedL raw =");
Serial.println(wSpeedL);
Serial.print("wSpeedR raw =");
Serial.println(wSpeedR);
}

//For Front wheels, frame 0x200, adjust front wheel average speed.
if (lMsgID == 0x200)
{
// copy speed data to wSpeedA
wSpeedA = (wSpeedA << 8) + cData[2];
wSpeedA = (wSpeedA << 8) + cData[3];

//debug printing
if (SERIAL_OUTPUT)
{
Serial.print("Front average speed CAN Raw, cData[2]..[3] =");
Serial.print(cData[2], HEX);
Serial.println(cData[3], HEX);
Serial.print("wSpeedA = ");
Serial.println(wSpeedA);
}
//divide average speed by 2.73 using binary scale factor, ((1/2.73)*4096) = 1500
wSpeedA = ((wSpeedA * 1500)>>12);

if (SERIAL_OUTPUT)
{
Serial.print("wSpeedA Converted = ");
Serial.println(wSpeedA);
}//end If

//Copy revised speed to data array
// memcpy ((byte*)cData[2], (byte*)(wSpeedA), sizeof(wSpeedA));
//memcpy (cData[2], (byte*)&wSpeedA, sizeof(wSpeedA));
cData[2]=highByte(wSpeedA);
cData[3]=lowByte(wSpeedA);

if (SERIAL_OUTPUT)
{
Serial.print("Front average speed Converted Raw, cData[2]..[3] =");
Serial.print(cData[2], HEX);
Serial.println(cData[3], HEX);
}
} //end if

//Divide Wheel speeds by 2.73 using binary scale factor, ((1/2.73)*4096) = 1500
wSpeedL = ((wSpeedL * 1500)>>12);
wSpeedR = ((wSpeedR * 1500)>>12);

//print data for debug
if (SERIAL_OUTPUT)
{
for (int mIndex=4; mIndex <= 7; mIndex++)
{
Serial.println("cData [4]..[7]");
Serial.print(mIndex);
Serial.print("-");
Serial.println(cData[mIndex], HEX);
}//end for loop
} //end If

//Copy wSpeedL and wSpeedR to working array, Note offset for start byte. Assumes both CAN frame and chip are little endian
//memcpy( (byte*)&bData[0], (byte*)&(wSpeedL),sizeof(wSpeedL));
//memcpy( (byte*)&bData[2], (byte*)&(wSpeedR),sizeof(wSpeedR));
bData[0]=highByte(wSpeedL);
bData[1]=lowByte(wSpeedL);
bData[2]=highByte(wSpeedL);
bData[3]=lowByte(wSpeedL);


//Print working array contents
if (SERIAL_OUTPUT)
{
for (int mIndex=0; mIndex <= 3; mIndex++)
{
Serial.println("bData[0]..[3]");
Serial.print(mIndex);
Serial.print("-");
Serial.println(bData[mIndex], HEX);
}//end for loop
}//end If

//Copy bData to data array
cData[4] = bData[0];
cData[5] = bData[1];
cData[6] = bData[2];
cData[7] = bData[3];


// Transmit Frame, print error message if CAN_ERROR is returned
if(canTx(cTxPort, CAN_DataMapping[nIndex].lTransmittedMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR)
Serial.println("Transmision Error.");


}

//Transmit Frames If low range is not active, or for non-matching frames
else
{
//If recieved port is CAN0, transmit on CAN1, otherwise transmit on CAN0.
cTxPort = 0;
if(cPort == 0) cTxPort = 1;

if (canTx(cTxPort, lMsgID, bExtendedFormat, &cData[0], cDataLen) == CAN_ERROR) Serial.println("Transmision Error.");
}// end if else

}// end for

}// end if

}// end for

}// end while

}// end loop

// ------------------------------------------------------------------------
// LED Data Traffic
// ------------------------------------------------------------------------
// Note: CAN0 --> LED1
// CAN1 --> LED2
//
void LEDControl(void)
{
if(pTimerLEDs.bExpired == true)
{
// Restart the timer
TimerStart(&pTimerLEDs, TIMER_RATE_LED_BLINK);

// Check for activity on CAN0
if(TimerActivity_CAN0 > 0)
{
TimerActivity_CAN0--;
digitalWrite(LED1, HIGH);
}// end if
else
digitalWrite(LED1, LOW);

// Check for activity on CAN1
if(TimerActivity_CAN1 > 0)
{
TimerActivity_CAN1--;
digitalWrite(LED2, HIGH);
}// end if
else
digitalWrite(LED2, LOW);

}// end if

}// end LEDControl

Midwestdrifter
05-26-2019, 11:39 PM
Calbiker, any idea what OA59 diode is in that diagram? I am not seeing any parts with that number. The source document lists it as a "Germanium Detector Diode". Part 1N34A comes up from a search, bits its not common.

calbiker
05-27-2019, 03:54 PM
The diode D1 is used as a rectifier. Say we have an ac signal that's goes from -7V to +7V. The diode blocks all the negative voltages. A germanium diode is used because it has a smaller voltage drop (0.3V) compared to a silicon diode (0.7V). We want as low as possible voltage drop across the diode. A large voltage drop will change the output square wave duty cycle (t_on/T) to something less than 50%.

D2 is a 5.1V zener diode that protects the amp from voltages greater than the supply.


There might be a better circuit for you. Do a search on zero crossing detector.

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRnPdqBWUbzgy4_tWeXI3ARj-QoMPyyT_83g7f9XeT5EK59VMEU-Q

The op amp requires +/- V supplies. R2 could be changed to the dual RC filter configuration seen in the previous circuit. D1 & D2 protect the op amp to +/- 0.7V. In other words, the signal is clamped to a diode drop. That's OK, as were only interested in the 0V crossing. The output signal is a true 50% duty cycle +/- 5V square wave.

As I understand it, this signal goes into Arduino to get its frequency modified. You can use a transistor to get signal back to a 0V to 5V square wave. The output of Arduino goes into a dual supply op amp to convert to a +/- 5V square wave. We're assuming the ABS module wants to see an ac signal. 741 is a very old op amp. There's probably something better out there now. Get package with dual or quad op amps.

https://www.ebay.com/itm/30W-DC-DC-Buck-Step-Down-Converter-5V-9V-12V-15V-3A-Dual-Power-Supply-Module/322825072832?epid=21007203095&hash=item4b29dfb0c0:g:0bQAAOSwZw1bvxGF

Edit:

Instead of zero crossing you could go with schmitt trigger. This give you noise immunity.

http://www.onegentleman.biz/Hardware%20Design/Op-Amp%20Oscillators/Osc%20Pics/fig-24.jpg

The key is that there are dual supplies to the op amp or comparitor. If the sine wave is symmetrical then output should be 50% duty cycle.

You'll need an osclloscope to check operation. The dual voltage power supply has advantage if Sprinter module likes to see +/- 5V waveform.

Midwestdrifter
05-27-2019, 05:59 PM
This circuit I posted earlier is a crossing zero detector. The Op-Amp is configured for single voltage operation, and has a couple of resisters for hysteresis on the output. I could incorporate a low pass filter into the input. The LT1017 has in input limit of -0.3V to 40V, so I need to make sure the negative half of the cycle is clipped off.
https://sprinter-source.com/forum/attachment.php?attachmentid=111719&stc=1&d=1556646329


For the output I guess I need to start with a 5V square wave, then look at ground isolation. If needed I will need an isolated DC-DC converter for the output stage.

calbiker
05-27-2019, 06:55 PM
The issue with this circuit is C1. It injects an ac waveform on a dc bias (from voltage divider R2 & R3). It also acts as a high-pass filter. It will attenuate lower frequencies. At 45 Hz, its resistance is 3.5 kohm. That may be ok since in-series with C1 is a 33 kohm resistor (3.5k << 33k). I believe the ac signal will get attenuated at the injection point.

V = Vac * (R2//R3) / ((R1 + XC1 + (R2//R3))
V = Vac * 5k / 41k = Vac * 0.12

If I got it right, assume the 45 Hz signal is 3V, then at the op amp it is 3V * 0.12 = 0.36V

The hystereses needs to be a lot smaller than 0.36V.

You'll need an oscilloscope to verify operation.

Midwestdrifter
05-27-2019, 07:11 PM
Yeah, my though is to drop the C1, and just use a low pass filter. I doubt there will be much low frequency noise on the circuit anyways.