Pita Van 4x4 Conversion

BajaVan

Observer
My name is Rob Peterson. I've been on this forum for awhile but haven't posted much. I joined this site back when I had a 91 big block E350 in the hopes of some day converting it to 4wd and building it into a cool adventure vehicle / tow rig. Long story short; life priorities changed, projects developed, some completed, some dissipated and I ended up selling my old van for something a little more respectable and reliable. That was about 5 or so years ago.

A little background on me; I'm an engineer by trade and have spent the first decade of my professional career in the off-road world, designing parts for Jeeps, Dodge trucks, and full on rock crawlers. A co-worker and I who had worked together for nearly 10 years at our old job got to the point where we decided we needed to try our hand at starting our own business. We both really loved the Sprinter platform but were disappointed in the lack of aftermarket components for them. So our goal was to start a company called Van Compass with one simple goal in mind; Bring high end suspension and off-road components to the Mercedes Sprinter world.

Since we are an upstart company, we feel forums are some of the best place to get feedback on projects we are working on. The more eyes we get on a project, the better the products we can design and bring to market. So we are going to do our best to explain the reason behind the rhyme on all the projects we are working on.

With that said, we figured it was about time to start a build thread on the affectionately named “Pita Van.” I’m told it started life as an On Star surveillance van. The gentleman I purchased the van from was in Fresno, CA and had a large Pita bread bakery. This little gem was one of 3 Sprinter delivery vans he had. Happily I was in the right place at the right time to score this 118” WB high top bread runner. Dirty, and neglected, the relatively low mileage short van was the perfect candidate for us to use as our development / test vehicle.



Phase one started with development of our Scout 2.0” lift kit. As some of you have seen already, this van was used to develop and test our 2” lift kit for the T1N platform. The lifted van with 33x12.5x15 tires went on several long road trips and was used extensively for nearly 5k miles straight in this configuration.



Phase 2 involved development of a fox shock package. With all initial prototypes being developed off this van, and final testing being done on my business partner’s “Tall Can” which is a 158” wheel base van, we are able to really dial in the mounting brackets as well as develop both a “heavy shock tune” for longer wheel base, fully outfitted vans and a “light shock tune” for smaller wheel base, utilitarian style vans.



Phase 3 and current stage of the van came about from a lunch meeting one of our friends in the off-road magazine world who has a deep love for 4wd vans. I had mentioned how I would like to develop a 4x4 conversion kit using all Mercedes parts, specifically, the running gear out of the Mercedes ML 4x4 SUV platform. Given that the ML uses a 4wd version of the NAG1 transmission, as well as a 2.64:1 low range transfer case, it seemed like we could get a lot of the parts we needed to make the swap happen and still be able to service it with off the shelf Mercedes parts anywhere in the world.
With Overland Expo West looming and that being the finish date goal in mind, we picked up a junk ML430 and set to work.





We stripped the ML of the front / rear suspension, transmission, t-case, front / rear differentials, front / rear drive shafts and cut out the suspension mounting points of the frame to use as a reference to develop our conversion brackets.






Step one was swapping the 4wd transmission in. We swapped bell housings from the 2wd Sprinter trans onto the 4wd ML trans. We retained the Sprinter torque converter as the diameter of the Sprinter’s flywheel is slightly smaller than that of the 4.3L V8 of the 430.







Step two involved removing the front suspension sub frame of the Sprinter and lots of head scratching. We temporarily welded some motor mounts in place and got to work with measuring, drawing and fabricating the conversion brackets needed to get the ML’s front suspension sub-frame in place.



With concept and initial design figured out, a couple hours on the torchmate and welding bench, we had the first stage of a rough bracket sorted out.





With the sub frame bolted in place as low as we could get it and still have adequate room between the differential and oil pan, we could start building upper control arm mounts. Again, careful measurements, lots of head scratching and a couple cuts through the “frame” and we had room to tuck the control arms in place. Matching the OEM geometry of the ML’s suspension, we were able to keep the van at just a 2” lift over stock 2wd ride height. So, 2” lower than a brand new factory 4x4 Mercedes van.







At this point came more tedious measuring, lots of removing brackets, re-installing brackets, test fitting motor mounts and sway bar mounts, measuring for shock placement and clearance. Tons of work, but the end result is a completed bench welded bracket that is basically your ML front conversion all in one piece. Sub frame, upper control arms, motor mount, shock mount and sway bar mount. Everything indexes off of 2 factory sprinter sub frame mounting points so it self-indexes in the correct spot.





Now on to the torsion bar mounts. I’m on the fence with the torsion bars and am curious to see how they do under the van. I’ve had plenty of torsion bar sprung vehicles and do like them for several reasons, but the main downside in this application is the loss of ground clearance. Because we ended up with such a low ride height, these hang down much lower than I would like them to be. I have plans for a front Fox coil over or air shock on the next go around, but we are sticking to our initial concept and keeping the Pita van 100% ML parts.





The torsion bar mount is completely removable and ties into the transmission mount. It is also the front gas tank mount. The gas tank did need to get shifted back to clear the t-case but all the original components still work. We just need to extend some wiring and hoses to get the fuel system all hooked back up again.


That brings us up to where we are at today. Right now we are painting brackets and working towards wrapping up the van to get it out to Overland Expo West in May. Fabrication is about 90% done. We still need to get the steering shaft hooked up and fabricate a rear gas tank mount. Then it’s onto the nitty gritty of hooking up brakes, fuel systems, wheel speed sensors and all that other fun stuff.

We still have a ton of work to do, and this is all a rough first go of it but so far I'm pretty happy with how it is turning out and can't wait to get it on the ground for a test drive.

-Rob
 

Haf-E

Expedition Leader
Very Interesting! Wonder if it would have been possible to still use the sprinter's McPherson strut instead of the upper A arm? seems like it would be cheaper / easier that way. Still would have the torsion bars I guess since the ML doesn't have the transverse spring.

Having a 2.64:1 low range is great - better than the new 4X4 sprinters! I like my first generation sprinter and the 5 cylinder better than the second gen version and would consider doing this. Thanks for pioneering it!

I hope the tranny plays nice with the sprinter's computer - curious how that will all work out.
 

Haf-E

Expedition Leader
I remembered that there was a "off-road performance" version of the second generation ML (164) which had real center and rear diff locks - but, even though they were built in the US, they were not offered here.

Perhaps they would be a source for a real rear diff lock? Not sure if the rear axle is the same or similar to the 163 ML or the sprinter.
 

BajaVan

Observer
Thanks for the positive feedback guys. It's definitely a big project, but we're hoping to get it manageable to a point where we could potentially sell a conversion kit for a reasonable price.


Very Interesting! Wonder if it would have been possible to still use the sprinter's McPherson strut instead of the upper A arm? seems like it would be cheaper / easier that way. Still would have the torsion bars I guess since the ML doesn't have the transverse spring.

Having a 2.64:1 low range is great - better than the new 4X4 sprinters! I like my first generation sprinter and the 5 cylinder better than the second gen version and would consider doing this. Thanks for pioneering it!

I hope the tranny plays nice with the sprinter's computer - curious how that will all work out.

Adapting the strut would be tricky since the ML's steering knuckle is very different than the Sprinter. That and the width constraints didn't leave us with a lot of options except for integrating the whole set up under the van. The upper arm set up on the ML's cycle much nicer than the strut configuration of the Sprinter. So that should make for improved handling and tire wear over the strut set up.

Trans issues have yet to be determined but I'm sure there will be some hurdles there. The harness plugs right into the ML trans, but whether or not everything plays nicely remains to be seen. Currently we are waiting for some steering joints to finish up connecting the steering. I'll try to get some updated pictures of everything cleaned up and painted a little later this week.

I'm a big fan of the older Sprinters too. 2.64:1 low range should be fun!

I remembered that there was a "off-road performance" version of the second generation ML (164) which had real center and rear diff locks - but, even though they were built in the US, they were not offered here.

Perhaps they would be a source for a real rear diff lock? Not sure if the rear axle is the same or similar to the 163 ML or the sprinter.

Unfortunately, the ML is IRS so it's not a very straight forward swap. Although, I do have plans to throw the IRS suspension under my van down the road just for fun. A rear locker would be really nice and it's on the to do list for sure.

-Rob
 

Haf-E

Expedition Leader
Too bad the ML wheels are 5 x 112mm - right? I guess you can add spacer adapters to go back to the sprinter 5 x 130mm wheels...
 

BajaVan

Observer
Too bad the ML wheels are 5 x 112mm - right? I guess you can add spacer adapters to go back to the sprinter 5 x 130mm wheels...

Yeah, the different wheel pattern and narrower width of the ML requires a wheel adapter to match the Sprinter width and pattern. If we get enough people interested in conversions, we will end up making a steel hub centric adapter specifically for this conversion.
 

Haf-E

Expedition Leader
One possible option is to use the front hub and strut assembly from a ProMaster van as they are FWD and the spring is at the top of the strut... They have the same bolt circle as a sprinter (5x130). So that would eliminate the torsion bars and the wheel spacer issues. Just an idea... I understand the benefits of double A arms over a strut.
 

BajaVan

Observer
One possible option is to use the front hub and strut assembly from a ProMaster van as they are FWD and the spring is at the top of the strut... They have the same bolt circle as a sprinter (5x130). So that would eliminate the torsion bars and the wheel spacer issues. Just an idea... I understand the benefits of double A arms over a strut.

I need to get my hands on a Promaster soon. :smiley_drive:
 

Haf-E

Expedition Leader
I need to get my hands on a Promaster soon. :smiley_drive:

I can't get past the ProMaster's rear axle - every time I see one I want to flip the axle to actually have some clearance - as it is I think it would get hung up too easily. Sure the clearance might be similar to the diff housing of some axles - but its all the way across... That might be a product you could offer!

Here is an image of the ProMaster's front suspension I found a while ago - I was thinking if you pulled out the sprinter's transverse leaf and added your spacer you might be able to fit the ML diff in the space provided - then use the ProMaster's hub assembly with the regular sprinter lower A arms and the ProMasters strut / spring assembly.

T440050.gif


You'd have to come up with a way to connect the ProMaster hub to the Mercedes diff - What kind of CVs are used on the diff? Are they the 6 bolt "Lobro" type as used on VW/Porsche/BMW? That would make it easier...
 

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