The Stovebolt Site Forums The Shop Area General Truck Talk What did I do wrong?

I'm posting this in the general truck talk area because the driveline thread seems to be down. I need your help, guys & gals. I reassembled my SM420 tranny for my '40 and the countergear assy seems to be locked up, nice & solid like. Everything else turns just fine. This thing only goes together one way, so I'm wondering what I could have done that's locking this baby up. I replaced all bearings when I rebuilt it. Thanks for your help.

If you have the top cover on you may have missed the reverse gear groove. If it,s not on the reverse gear may have slid back. Remove the rear cover & see if that frees it up. Sometimes the snap rings on the outside of the bearings are different from the originals & you have to use the ones off the old ones.

Wrenchbender, et.al, I think I figured out why the lockup. The roller bearing(s) I bought for the countershaft gears may be just a few thousandths thicker than the originals. I removed the rear cover/u-joint housing and it spun freely. Then, just to make sure I put it back on and, sure enough, it locked up. So then I took out the thrust washer and reassembled and it spun freely. It could only be the bearings. Now the dilemma is that I tossed the originals. Not that they were any good, but it would be nice to have them for comparison purposes. I did compare them for width at the bearing supplier's place but to me they looked identical. I should have measured them or at least laid a straightedge across them. I guess my question at this point is this. Does anyone make a thinner thrust washer? Is the thrust washer required? I think it probably is because without it there's alot of end play. Let me know your thoughts. Thanks again.

OK, so here's the plan. I went to Napa Auto Parts today and bought some thick gasket material. I'd say it's maybe 3/32" thick. I'll make a new gasket for the rear cover and try that out. I think that should do the trick. I'll keep you posted on what happens.

Update to anyone who's interested: the thicker gasket did the trick. Had to make my own and it ain't as pretty as the one in the kit, but the tranny now spins freely in all gears! I'm a happy camper. Now I can start putting the motor back together.