4WD Conversion Proposal

[Midwestdrifter]

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]

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]

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]

Originally Posted by Midwestdrifter

...

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

[Aqua Puttana]

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]

Originally Posted by Aqua Puttana

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]

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]

Originally Posted by OldWest

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.

Originally Posted by Tooth Fairy

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.

Originally Posted by jackbombay

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.

Originally Posted by Aqua Puttana

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.

Originally Posted by DieselFumes

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]

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]

I thought I would post some details on the 4x4 system up.

Here is a photo of the front differential. From this thread.



Here is the front uprights.



Here is the a view of the front subframe.



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 thread.



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.



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!



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



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).