4WD Conversion Proposal

Midwestdrifter

Engineer In Residence
Getting the last few bits welded on.







Working on the sway bar mounting. May need to do a little trimming. For some reason the OE sway bar bushings were too small, and I can't find an OE bushing for the 800s with 36mm OD. The 900 bushing fits, but I need to figure out the amount of compression it needs for a tight fit.

 

Midwestdrifter

Engineer In Residence
Sway bar mounted. The only welding/fab work left on the subframe is the UCA shims. Looks like I will need 3/16" shim on the rear, and 1/4" on the front bushing.


 

Midwestdrifter

Engineer In Residence
Playing around with my el-cheapo flare kit. I need to polish the vise, but it does a passable bubble flare.


Running the BJs through their paces. Assuming high angle CVs are used, there is about 9.5" of travel before the BJs bind.



Bit of a hack to add a droop stop. Once I get the other side done, its time to prep for paint.

 

Midwestdrifter

Engineer In Residence
And that's a wrap folks.



I needed to do a bit of grinding to open up the front LCA bushing holes. I guess the front bushing is not quite parallel with the rear. Now to get this thing prepped for paint, and make a few spacers to get everything nice and tight.
 

Midwestdrifter

Engineer In Residence
Spent way to much time grinding and sanding. Scrubbed and degreased. I am still not very happy with the cleanliness of some of the tight areas. I will do a quick look for a local shop that does media blasting.











 

Midwestdrifter

Engineer In Residence
Have it powder coated if you feel like it's done. They will blast it before coating!

Two issues with that. First, I will certainly need to make a few minor changes during fitup. So powder coat would add a fair bit of extra time, during which I have a van with no front suspension, and nothing to hold the engine up (unless I bolt the subframe back on).

Second, Powder coating with all the sharp-ish corners will probably chip quickly. Once its compromised, its hard to repair/touchup. Without a sacrificial coating the rust spreads under the coat.

For a final product powdercoat makes sense, its not ideal for prototypes though.
 

flyag1

Active member
I will agree trying to weld on a forgotten tab is a bear... grinding down to metal and then you still get smoke and nasty gasses.

I will say don't fret touch-up. I know of a car shop that powder-coats body parts as in fenders and such. If they are fighting rust pits they have the part powder coated then sand and paint. The powder coat is so thick they can sand most off and leave the pits filled in as though they applied 10 cost of primer. I do a lot of square tube builds and when its time to paint off to powder coat it goes. Headed that way in the AM....
 

Nautamaran

2004 140” HRC 2500 (Crewed)
That’s really coming along! :cheers:

Good call on sending it out for cleaning. You’re still a LOT of scotch-brite & time from being ready for paint... and a media blast will likely produce a better surface texture for your primer anyway.

Not helpful now, but at the shipyard I did my work terms in during university they always ran steel parts through a beadblasting line before they went into any sort of complex assembly. The mill scale has to come of sometime, and it’s SO much cheaper to clean parts that are rolling down a conveyor than to climb around inside a double bottom after welding.

(The final welds inside those assemblies were often pretty hard to get to, so the same yard had quite a few dwarfs among the welding ranks. They spent a lot of time working under air in a pretty hellish environment, and were paid top scale for their trouble.)

-dave
 

Midwestdrifter

Engineer In Residence
Greetings once more. I just noticed its been almost a full year since I started down this design track. I think I am making good time, but I had hoped to be done by December.

A quick update. After trying to find a shop to PC and/or blast the subframe, I gave up. Most are closed or booked through the first week of Jan, or don't want to do a one-off. I wire wheeled and scuffed everything I could reach. Then I sprayed three coats of chassis saver urethane. I got a little bubbling due to uneven curing (sun is directional after all). But it came out okay. I plan to hit it with some rubberized undercoat a bit father down the road.



I am going to do the final suspension/diff/rack test fit to finalized the spacers/shims today. I am off work till the 1st, so I will make decent progress. I just ordered wheels for the front, CV spacers, and studs for the tie rod adapters.

If everything arrives next week, I may try to mate everything up next weekend.
 
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I wonder if a truck bedliner product would be effective as a longtime protection over that beautiful paint job you have on that undercarriage. I guess the rubberized undercoating will suffice.

Thanks for your ongoing design to make a true 4 wheel drive T1N Sprinter a reality. Many of us are envious of what could be possible. Since you have begun this effort, Iglhaut/Alrad has come to the States with a $50,000 alternative that offers differential lockers that the MB AWD systems do not. It is hard to imagine anyone with a T1N would spend that much for such an aged model of van.

Although I have read all of your posts, and sometimes two or three times, I have to admit some of the descriptions may as well have been in Greek. This is not due to your writing, rest assured. I am sure you have learned much more than you thought you would have ever learned, kind of like knowing what not to do. Failures do make for a lasting impression.
 

az7000'

2007 Navion on a 2006 3500 chassis
Sorry I didn't give you another option sooner, check out Steel-it stainless coating in a can! We race off-road and their website shows our mechanic spraying a full chassis and all the parts. The best part is when you chip it up you can just touch it up from a can and you can weld right through it. They use it in food plants and power wash it constantly. The website has a link for a sample kit too.

Amazing build and progress!! Your job looks great

https://www.youtube.com/watch?v=LnLSHVQobHo&feature=youtu.be
 

Midwestdrifter

Engineer In Residence
Urethane bedliner products have a tendency to chip with high speed rock strikes. So i prefer of rubbery material (like the OEM undercoating). I need to recoat my rear axle. Its been sandblasted by lots of dirt road driving. The factory zinc plating under the paint has kept the worst of the rust at bay, buts its almost completely consumed now.


Brief update. Control arms all fit. I ended up tacking some 0.2" spacer/washers to the bushing body. I will adjust the model for a tighter fit, but this was expedient.



Diff and rack are fitted up. I am using the rack off the van, so this is an old worn rack for testing. I also bent and flared new hard lines for the rack, which clear the diff body. I also tested a 1/2" CV spacer, and it seems to be a good thickness. I may go with a 3/4" spacer, but that can be changed down the road easy enough.















Still no word on the rack adapters. They are supposed to ship next week currently... Wheels should arrive tomorrow. I am not sure if I will just transfer my current (almost worn out) tires, or if I want to take guess at what size will fit. Current thoughts are a 265/70R16. Though I think a 265/75R16 will fit if I remove the front mudflaps (they need to come off for other reasons). The safe bet is to mount the current 245/75s and see what clearance I have, both to body metal and suspension.



Current track width is looking to be 2-3" wider than original. Once I get it measured, I can get the rear adapters made. I think I will go with studs to match the front. Might as well be consistent. I have already had one bolt hole stripped by ham-fisted warehouse workers.
 

wrangie

New member
I need to recoat my rear axle.
Well, after some failures with the "mighty" POR15 , i reccomend you the EM121 Rustbuster.
It s simplly unbelievable.After 2 years it s solid as a Rock and it looks like it become one with the chassis.
You can use as well the Noxudol for the interior spaces (hidden places)
Attached you will find the comparison test with it s competitors (including POR15) over a 3 year period
 

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Midwestdrifter

Engineer In Residence
Got the wheels today. A bit heavier than I thought. They fit fine, but the offset is a bit lower than I expected. Track width is about 69". I was aiming for 67". There is still a bit of backspacing available to the suspension, though I need to see what the calipers fit like. Going with a higher offset, depending on tire width I may get rubbing on the UCA at full droop and lock though. I think these wheels are about 26mm offset. So 50-60mm should do the trick. Though I am not sure if wheels are available at that size for reasonable cost.



 

Midwestdrifter

Engineer In Residence
I grabbed a Dodge ram 2500 wheel with 245/75R16 tire from the junkyard. This one is around 43mm offset. It fits fine, but the center bore is larger, and the lug seats are a different diameter. After giving it some thought, if I can keep the track width at 69", I think I am okay with that. Its about 3" larger than stock, so I will need a 1-1.5" flare to keep the rocks under control.



I think I want to get the suspension mounted up before I start playing around with wheels and tires too much. There are too many unknowns with wheel well clearance etc.











 

Midwestdrifter

Engineer In Residence
On the hard limit of the knuckle and LCA, the brake line hits the shock. I will probably need to reduce the rack travel some. In addition I will probably move the brake line for a bit more steering angle.




I will have a go at bending the steel hard section, but I am not hopeful. I have another idea though. I could get custom lines made, but it looks like the 1500 chevy brake lines are all flex from the banjo, so I could run them over the top of the caliper instead. The brackets look pretty to right as well.
 

Midwestdrifter

Engineer In Residence
It appears that GM changed the brake line routing at some point o the 2500s. All the new parts go around the side, while the original lines from the donor go next to the bleed port. it would have been nice to find the older style avaialble new, but no luck sadly.



The 1500 lines fit fine. I needed to clearance grind a mm or two from the banjo outside edge, and move the brackets a bit.








The hard line placement isn't ideal. The best position would be on the rear of the UCA, but the routing would be too tight a radius. So I will need to run the hard lines up the wheel well. The other option is to run them inside the engine compartment, and drill a pass through into the wheel well.
 

Midwestdrifter

Engineer In Residence
Rack adapters are here. Looks like I need to adjust the countersink slightly for the radius at the thread root, but otherwise fit is good.



 

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