Sprinter 4WD Conversion Idea, GMT-800 IFS.

[luthj]

Got it mostly together. Far enough to measure the backlash at least. If I am measuring it correctly, its 20 thousands at the yoke, which is 10 actual. spec is 6-10 without me messing with the adjusters. Which makes sense, it was higher before due to the failed bearing, and I am using the same gears and pinion bearings. I will check the contact pattern over the weekend. The lockers air transfer collar makes it annoying to assemble, as once you put the right case half on, you really can't take the diff out of that half again, at least not easily. They also use 2 tiny O-rings to seal the bulkhead fitting. They are very difficult to fit over the end of the copper tube. So I needed to chamfer the tube, and slightly enlarge the brass spacers ID.




Here is the failed bearing outer race.

 

[shade]

Here is the failed bearing outer race.

Just a little rough.

I wonder how wide you'll be grinning the first time you flip the locker switch for real. I know you've gone far in RWD-open, but a locker almost seems like a necessity for a RWD vehicle like yours traveling off of good pavement.

 

[luthj]

The thing about longer wheelbase unibody vehicles, is that they don't flex much. That's good for handling and not breaking cabinets, but it also means the van will tripod quite easily. Having a rear weight bias helps, but I think the locker will be a very useful addition when I have 1 front wheel 10" off the ground. You may be surprised how often that happens. Though, with a front sway disconnect and another inch of front travel, its going to happen less often.

 

[luthj]

 

[b dkw1]

Coast side looks good but the drive side looks a little deep. Odd.

 

[luthj]

Yeah, it didn't match any of the common patterns. I would expect an equal shift in the opposite direction on the coast side? Maybe excessive wear on the drive side?

 

[b dkw1]

I would probably have backed the pinion out a little to get the drive side closer. It's more important than the coast side. But who knows, maybe under load it will move out enough to center up.

 

[Mwilliamshs]

I would probably have backed the pinion out a little to get the drive side closer. It's more important than the coast side...

Yep, me too. If it moves enough to be normal in forward, it'll move enough to be sketchy in reverse. Think backing up a slick hill where the rear end doesn't have traction due to weight transfer but the front is very heavy so has good grip.

 

[luthj]

 

[luthj]

Hoping to get some detailed teardown results on the sprinters trans. It drives fine, some mild TC shudder, and the occasional rough 2-1 downshift. 185k+ miles.

 

[b dkw1]

Oil hole in the output shaft, failure point.

 

[mountainhick]

Oil hole in the output shaft, failure point.

How so? Clog?

 

[b dkw1]

How so? Clog?

Stress riser, promotes cracks. 4L60's along with other tranny's have a real issue with this.

 

[mountainhick]

Stress riser, promotes cracks. 4L60's along with other tranny's have a real issue with this.

Hmm, I never heard of this failure in a Sprinter NAG1. I guess with the beefing up of everything else in the drivetrain, and the potential torque 4 wheelin' could become a problem. I don't see and immediate solution though, just something to be aware of?

 

[luthj]

With the intermediate shaft allowing minor misalignment, there isn't much load on the output shaft bending wise. I will give that area a good look, but I don't think there is much risk compared to the other common 4x4 transmissions, where the output shaft mates directly with the Tcase input gear.