by justin.loehlein » Tue Jun 25, 2019 6:48 am
Just to close this out, I ended up making it work. We'll see for how long. Because the driveshaft is 2 pieces and the slip yoke is on the rear half, we figured there shouldn't be a lot of in/out force on the flange at the output shaft of the transmission. That, plus the fact the worse that happens is I destroy a Getrag made me a little more comfortable experimenting.
Mounting the trans was easy. I just used the 4x4 mount and got rid of the 1" riser on it. The resulting driveline angle is the same as the auto trans we removed.
I got the output flange and u-joint carrier from a G56 (part numbers 5142860AB, 5183074AB). In order to attach it, I welded a 16mm stud to the output shaft of the Getrag (I cut down a bolt and "machined" a nub that centered it in the existing hole on the output shaft). I also cut down a spacer that fit inside the flange and would hold it off the weld (so I was bolting to a flat surface). I had to cut the flange shorter so it didn't sit too deep and I welded the washer that comes with it to the surface of the flange so when it was bolted solid, it wouldn't slide towards the transmission.
That all bolted together fine and seems fully reversible. I had the driveshaft shortened and balanced and have been driving around for a few hundred miles. Night and day difference. Overall, I'd say not a really practical solution, but since I had the 4wd Getrag laying around and I found the flange and yoke for ~$200, it made sense.
It would have been less sketchy to take the mainshaft/output shaft out of the transmission and have a machine shop cut or EDM in the threads to accept the bolt that comes with the G56 output shaft, but I didn't want to go through the effort of tearing the transmission apart.
1990 D250, 5 speed
1993 W350 waiting to be restored