Sprinter 4WD Conversion Idea, GMT-800 IFS.

luthj

Engineer In Residence
My vans trans is very clean (regular fluid changes), and I cleaned the plate once before. I will flush it, ohm out the pins, and install it. There is some risk, but its a 150+$ part, and I am trying to maintain the illusion of considering my budget. Bad conductor plate contamination generally means the trans is coming apart. Early models (pre 2001?) didn't have the speed sensor traces encapsulated in plastic, so metallic fines build up on them, causing erratic operation more frequently than the updated design. While its messy, I can swap a conductor plate in the field if necessary. I have seen photos of several badly contaminated conductor plates, not something that can be cleaned at that point.

The sprinter variant uses a "special" ATF. Its basically Dex 3 with a friction modifier, and a bit lower viscosity. The sprinter uses slightly different material on a couple clutch plates, though I couldn't tell the difference with the Jeep trans. The biggest difference is probably in the torque converter, and the TCMs programming. Lots of sprinter owners report no issues using Valvoline maxlife ATF, so the MB fluid isn't that special.
 
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shade

Well-known member
Lots of sprinter owners report no issues using Valvoline maxlife ATF, so the MB fluid isn't that special.
The same ATF has worked well in place of Toyota's overpriced house brand, too. I've got four gallons of Valvoline Maxlife ATF (Walmart has a good price) and a pump sprayer ready for mine.

It's not a surprise to see ATF be another money grab, but it's poor form by OEMs, in my opinion. It's not like they're feverishly working away at a refinery, developing the absolute best fluids for their products, and most fluid changes are done at a dealership, if at all.
 

luthj

Engineer In Residence
Some transmissions end up with odd behavior due to software, so custom fluids are a cheap (for the MFG solution). MB charges $$$$$$ to get BEVO approval for fluids, which is dumb in my opinion. In the case of the sprinter, the TC clutch is very active, and will chatter/vibrate if the wrong fluid is used. That being said, the Valvoline product is a great value, and covers an surprising array of vehicles.

Some of the high efficiency automatics need some specific fluid (hyundai has a couple). It wouldn't be so bad, but they won't share the formulation with third parties. And the third parties aren't going to drop the cash to buy a bunch of brand new $10k transmissions for long term testing!

Its against my personal code to pay 20$ a quart for fluids. That's giving starbucks a run for their money!

As far as OEM labeled fluids go, they usually aren't that expensive if you have a dealer account (about 15-20% more than the non-oem package). But many dealers go crazy with the markup on fluids, often 50% or more. Its one of the ways they pad their profit margin on quick and easy service visits.
 

shade

Well-known member
Some transmissions end up with odd behavior due to software, so custom fluids are a cheap (for the MFG solution). MB charges $$$$$$ to get BEVO approval for fluids, which is dumb in my opinion. In the case of the sprinter, the TC clutch is very active, and will chatter/vibrate if the wrong fluid is used. That being said, the Valvoline product is a great value, and covers an surprising array of vehicles.

Some of the high efficiency automatics need some specific fluid (hyundai has a couple). It wouldn't be so bad, but they won't share the formulation with third parties. And the third parties aren't going to drop the cash to buy a bunch of brand new $10k transmissions for long term testing!

Its against my personal code to pay 20$ a quart for fluids. That's giving starbucks a run for their money!

As far as OEM labeled fluids go, they usually aren't that expensive if you have a dealer account (about 15-20% more than the non-oem package). But many dealers go crazy with the markup on fluids, often 50% or more. Its one of the ways they pad their profit margin on quick and easy service visits.
A friend of mine has a large transmission shop. He always uses whatever the OEM recommends unless the owner specifies something else, and signs a waiver. He said there are good alternatives to many OEM ATFs, but it's not worth his trouble to assist with the experimentation.
 

luthj

Engineer In Residence
Made some more progress.

I drilled both Upper BJ bores deeper/bigger to accommodate the ford UCAs.



I Hack... modified the sprinters cable bracket to fit. I left a bit of a tab on the lower side. I was considering putting a splash/brush guard over the shift lever down the road.

 

shade

Well-known member
I can't recall if you have any skid plates, but skinning your new sub-frame in 1/4" aluminum might be a good idea. I've found it offers good enough protection from hard hits without adding much weight.
 

luthj

Engineer In Residence
I do have 1/4" AL skids. They aren't the best fit, but I will probably make them work.

It doesn't look like there are any common 1350 pinion yokes for the 9.25 IFS. The current yoke is a 3R, which isn't much different than a 1350, and should be good enough for my application. I can use a conversion joint. Its another spare UJoint to carry, but those aren't expensive or large.

I believe Spicer 2-4-5441 will fit on the Tcase output. Its a 1330 CV yoke.
1567380195679.png

Its listed as a spline diameter of 1.401, and 32 splines. The OD is 1.875. I measured the Tcase, and it reports about 1.398" on the yokes spline valleys. The current OD of the dust shield is 1.94, and the yoke is 1.875. So it looks like its the right one. I would need to transfer the dust shield (not sure it will even come off...)

I may have found a 1350CV yoke compatible with the 242, but I need to track down the OD.
 
Old 208 yoke, works perfectly in the T case, even same size seal. Lucked out finding one in a local parts yard. They are an older model part, the one I found needed some sanding/polishing. Here's one on ebay.

And: https://www.ebay.com/itm/NP-208-Fro...315292?hash=item1efb03489c:g:TfEAAOSwz7hc5WFo

You can get a flange double cardan that mounts to this flange yoke... 3 1/8" pilot circle, 4" bolt circle if I am remembering right. It is close to the shift linkage, but I think there's clearance.
 

luthj

Engineer In Residence
Good info, thanks.

There is a chance this unit may be the right size. Its CV compatible, though not sure which style.


1567432739138.png

I am going to call up a driveshaft shop to see what they suggest. I plan on order a custom front shaft, so might as well get their input before I start swapping parts.
 
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luthj

Engineer In Residence
I did some measuring under the van. Looks like the fuel tank needs to move back about 7" minimum, likely 9-10". Its hard to tell, but the shift shafts bulge on the back of the case may interfere some.



I measured the trans/tcase stackup. It is about 46" long. That puts the tail housing pretty much right in this tight area in the floor support. The good news is that the bulk of housing is forward of the support member, so I don't think it will need trimmed. Though I may need a few minutes with a BFH depending. The rear driveshaft will probably be around 76" long, hard to tell without the yokes in place.




I measured the tank fill hose. The coupling is 2.25 OD, so the hose is likely 2.125-2.25ID. I will need 2 soft elbows, and a coupler. Should be a pretty easy run though. The vent hose is out of reach, but looks like 3/4", and should also be easy to extend. The return/feed soft lines are about 36 and 24" respectively, and will need extended. I think they are 3/8" ID.

As far as mounting the tank goes, I may move it back 12", as that overlaps with the next set of floor supports pretty well. i will probably make new straps from some 1/16" steel strip, and some angle iron brackets. I would like to make them bolt on, but it may be more expedient to weld on brackets. I dislike that approach, as is compromises the coatings on the back sides of the floor supports.
 

luthj

Engineer In Residence
Okay, another 100$ parts order. 2 elbows and coupler, and 3/4" vent line. I will submit a separate order for high pressure fuel line, as I need to figure out what I am doing with my add-on filters.
 

shade

Well-known member
I dislike that approach, as is compromises the coatings on the back sides of the floor supports.
Pump them full of Fluid Film or another oil based corrosion inhibitor and they should be ok for at least a few years unless you like playing U-boat Commander.
 

luthj

Engineer In Residence
You would be surprised how often the van gets a undercarriage level irrigation. I could rig up a tool to spray coating inside those areas as well. I find that bolt on (or rivnut) style attachments provide more flexibility on one-off prototypes like this. Despite being a bit quicker, I dont like welding on my back...
 

luthj

Engineer In Residence
Good news. My Shocks/springs have arrived at the vendor, and will be tuned/shipped by the end of the week. I guess I had better get moving on the trans carrier and fuel tank modifications.
 

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