Van Compass "Pita Van" 4x4 Conversion

Desertbound

Active member
Hey guys. Long time lurker here but this is my first post on Sprinter Source! Just wanted to start by saying how great this forum is. There is simply a ton of great information from a lot of smart people in here. My name is Rob Peterson and I’m the Co-owner and engineer at Van Compass LLC. I’ve spent the first decade of my professional career in the off-road world, designing parts for Jeeps, Dodge trucks, and full on rock crawlers. Mark (Keepmoving on here) and I had worked together for nearly 10 years at our old job and we 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 with Van Compass is simple; Bring high end suspension and off-road components to the Mercedes Sprinter world.

As many of you know, we are an upstart company and want your input on everything we are doing! The more we hear from you, the better 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 of our products and projects. There are no secrets here. We want to show you our products in detail every step of the way so that you have confidence about all of our products.

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. Maybe one of you could shine some light on that theory. 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 many 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 without issue.



Phase 2 involved development of our fox shock package. With all initial prototypes being developed off this van, and final testing being done on Mark’s “Tall Can” 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 our hope is to get this dialed to a point that we can offer this as a very complete, polished kit with detailed instructions so that a person who is confident with a welder and tools can perform this conversion themselves in their driveway in the matter of about one months’ time. Let us know what you guys think and please ask away! We want your feedback and thrive off the input.

Come check the Pita Van out in person in our booth at Overland Expo West in Flagstaff AZ May 20th-22nd.

-Rob
 
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vanski

The most interesting member in the world
subscribed!!! Let's make this happen VC. About time someone is doing this!
 

Midwestdrifter

Engineer In Residence
I have to commend the creativeness and craftsmanship. :rad: Definitely subscribed.

I am guessing import restrictions, or parts availability is the reason you are not using the factory 4x4 configuration? I figure the bolt on nature would be cheaper (considering the labor) than the modification heavy approach you are using?

How are you approaching control of the transfer case? Transplant the system from the donor? Or a custom solution?
 

Desertbound

Active member
Thanks for the compliments guys!

I have to commend the creativeness and craftsmanship. :rad: Definitely subscribed.

I am guessing import restrictions, or parts availability is the reason you are not using the factory 4x4 configuration? I figure the bolt on nature would be cheaper (considering the labor) than the modification heavy approach you are using?

How are you approaching control of the transfer case? Transplant the system from the donor? Or a custom solution?

Part availability was one of several reasons. ML's are dime a dozen, cheap and very easy to source parts for both here and abroad.

The ML has a transfer case control module, but we are going to try to cheat the system and simplify it to just engage 4LO at the push of the button. It has an electric motor to engage from 4hi to 4lo. We kept the module and button (which is the same size as the factory sprinter dash switches btw :thumbup:)

I'm hoping to simplify it and just utilize what is needed for switching from 4hi to 4lo and lighting up a dash light to notify of engagement.
 

Midwestdrifter

Engineer In Residence
No personal experience, but I suspect that all you need is position sensing and motor drive control input/output. A combination timer/latching relay in with a SPDT switch may work. I agree that using the factory module sounds too complicated IMHO.

That low ratio is fantastic. All you need is a TBD/LSD for the rear. Hmm, someone needs to import some sprinter compatible Quaife TBDs? I would buy one. :drool:
 

vanski

The most interesting member in the world
Will the ASR and ABS be available on all 4 wheels? Wondering how the ECU is going to interpret the 'new' information.
 
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Desertbound

Active member
Will the ASR and ABS be available on all 4 wheels? Wondering how the ECU is going to interpret the 'new' information.
The ML has individual tone rings at each wheel same as the sprinter. Whether or not the tone ring count and interpretation will all jive remains to be seen. Hopefully be tackling that project by the end of the week.

Currently we are waiting for some steering shaft components to show up so we can get the rack connected to the steering wheel.
 

twocyli

New member
Very interesting - the one thing I can't figure out is that the ML is listed as having a 3.70 diff ratio and the sprinter is listed as being 3.73? I guess that is close enough since there is a central / non-locking differential?

3.70 = 37 ring 10 pinion

3.73 = 41 ring 11 pinion

I suppose those Sprinters with the 4.11 diff ratio will need to change to the 3.72 as I don't think there is a 4.11 ratio even in the European versions of the ML series.

Here is a great site with lots of info:

http://4x4abc.com/ML320/ML_specsIII.html

 
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Desertbound

Active member
Very interesting - the one thing I can't figure out is that the ML is listed as having a 3.70 diff ratio and the sprinter is listed as being 3.73? I guess that is close enough since there is a central / non-locking differential?

3.70 = 37 ring 10 pinion

3.73 = 41 ring 11 pinion

I suppose those Sprinters with the 4.11 diff ratio will need to change to the 3.72 as I don't think there is a 4.11 ratio even in the European versions of the ML series.

Here is a great site with lots of info:

http://4x4abc.com/ML320/ML_specsIII.html

You hit the nail on the head. Since it is a 48 / 50% split and not a true locking transfer case, I think we will be ok and not get any adverse effects. Unfortunately, as it stands now, we will have to offer this swap at the 3.73 rear gear ratio only. Again, if there is enough interest, we may look into making a front 4.11 gear set to mesh with both sprinter rear axle ratios.

That website was very handy in helping us determine if this was a worthwhile endeavor. Cheers to the individual who put that together!

Spent the past couple days getting the first prototype rear bumper knocked out while we were waiting for steering parts. Few more details, and it can all come off and go to powder coat.

 

twocyli

New member
You hit the nail on the head. Since it is a 48 / 50% split and not a true locking transfer case, I think we will be ok and not get any adverse effects. Unfortunately, as it stands now, we will have to offer this swap at the 3.73 rear gear ratio only. Again, if there is enough interest, we may look into making a front 4.11 gear set to mesh with both sprinter rear axle ratios.

That website was very handy in helping us determine if this was a worthwhile endeavor. Cheers to the individual who put that together!
I did a bit more research and it turns out there are quite a few vehicles with slightly different front rear ratios - even in part time 4WD setups without a center diff - supposedly gives better front steering control? But, as you said, the center diff can easily make up for the 1% difference involved here.

Interesting that the first MLs had a 50-50 split and then they went to a 48-52 split in 1998.

Looking forward to seeing more progress!
 

twocyli

New member
I happened to have had a chance today to compare the front suspension of a Promaster and a Sprinter in a parking lot - there are several differences which would make the idea of using the Promaster hub and strut assembly for a 4wd conversion that would make it more challenging - mostly that the ball joint on the Sprinter mounts UNDER the A arm and on the Promaster it mounts on TOP... not impossible - just trickier.

If you could put the ball joint on top of the Sprinter's A arm - they would need to be at a steeper angle to have the same clearance under the engine/front diff. This would affect the suspension geometry and possibly affect the handling. The ball joint on the sprinter was also closer to the wheel rim - on the Promaster it seemed farther inward. That would result in the wheels being moved outward also - perhaps too much.

So - I think your approach of using the ML suspension is probably the best - especially since they are available cheap and you need the tranny / driveshafts from one anyways. There are several on the Seattle CL for under $2000 that say they run well.
 

Desertbound

Active member
I want that bumper with a locker on it and a step.
How would you like to see the step built differently?

The bumper does have a step built into it as is. The top "step" of the bumper is about 5-1/2" down from the floor of the van. We are really trying to make our parts with off road performance in mind, so high ground clearance while still allowing for aided entry is what we are trying to design around. Every bumper has a built in hitch so it's easy to add an additional hitch step if needed.

We will likely be building all our bumpers with the option of dual swing outs as well.

-Rob
 

Desertbound

Active member
I happened to have had a chance today to compare the front suspension of a Promaster and a Sprinter in a parking lot - there are several differences which would make the idea of using the Promaster hub and strut assembly for a 4wd conversion that would make it more challenging - mostly that the ball joint on the Sprinter mounts UNDER the A arm and on the Promaster it mounts on TOP... not impossible - just trickier.

If you could put the ball joint on top of the Sprinter's A arm - they would need to be at a steeper angle to have the same clearance under the engine/front diff. This would affect the suspension geometry and possibly affect the handling. The ball joint on the sprinter was also closer to the wheel rim - on the Promaster it seemed farther inward. That would result in the wheels being moved outward also - perhaps too much.

So - I think your approach of using the ML suspension is probably the best - especially since they are available cheap and you need the tranny / driveshafts from one anyways. There are several on the Seattle CL for under $2000 that say they run well.
The ML just ticks so many boxes, and provides us with all of the drivetrain components needed. The benefit of having every wear / service item being a mercedes part is invaluable in my eyes.

I've built a bunch of custom off road vehicles with all sorts of different components from different manufacturers and it was always such a pain when it came time to prep and service something. With this conversion it is simple; from the flywheel up into the vehicle, it is all Sprinter. From the torque converter down to the wheels, its all ML320. No guess work involved when its service time.
 

twocyli

New member
I agree that is very helpful and would probably make servicing easier in that you can tell the mechanic its all mercedes still. The only concern is that the ML is a 6000 lb GVWR vehicle and I've loaded my sprinter up to 10,000 lbs more than once. Typically running about 6500 lbs when camping with people on board.
 

Desertbound

Active member
I agree that is very helpful and would probably make servicing easier in that you can tell the mechanic its all mercedes still. The only concern is that the ML is a 6000 lb GVWR vehicle and I've loaded my sprinter up to 10,000 lbs more than once. Typically running about 6500 lbs when camping with people on board.

Very, very true. I am continuously amazed by just how much weight a Sprinter can haul given its size and relatively small drive train components.

We are going to try to do some detailed side by side comparisons when all is said and done between the front end components on the Sprinter vs. the ML to see where the ML parts may or may not fall short in strength which could jeopardize vehicle payload abilities.

Again though, this is all in very early stages. This is a kit that we thought would be fun to develop but it was really to give us a long term project while we had downtime between waiting on prototype parts for our more standard bolt on parts that we have in the works.

-Rob
 

Paul_E_D

Member
How would you like to see the step built differently?

The bumper does have a step built into it as is. The top "step" of the bumper is about 5-1/2" down from the floor of the van. We are really trying to make our parts with off road performance in mind, so high ground clearance while still allowing for aided entry is what we are trying to design around. Every bumper has a built in hitch so it's easy to add an additional hitch step if needed.

We will likely be building all our bumpers with the option of dual swing outs as well.

-Rob
Ah. After a second look i realized tha the step was integral. I was just thinking a little lower in my vision. I do understand the clearance issue...
 

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