Having some problems with the rear u joint on my 72 Cutlass 8.5 rear. I replaced both front and rear u joints (ac delco #45U0136) while I had the driveshaft out for a transmission R&R. When i put the driveshaft back in I noticed at the pinion yoke there was no way I was going to be able to put the snap rings on the inside of the u joint caps, just would not fit within the hold down straps, like the u joint was too wide. Ok so I thought maybe just the clamping force of the straps would hold the u joint in place. Wrong! After a few mile ride the rear driveshaft u joint decided to exit the pinion yoke. After a tow truck ride home I pulled the driveshaft out. Every brand of u joint listed for the car shows the same u joint part number for both front and rear. I'm stumped! Any ideas guys? Could use some help! Thanks in advance!

 

Sometime when a U-joint seems to wide a roller has slipped out of place and is laying in the bottom/end of the cap. This prevents the cap from going on completely and then the joint becomes too wide.

Test fit a new joint in the pinion yoke before installing in the driveshaft.

Good luck!!!

 

It's been awhile but a quick update. I put a new ujoint in and paid very close attention lol to what I was doing and everything worked out ok. No way of knowing what exactly happened but it had to have been a roller slipped out of place in the cup. Lesson learned, thanks for the reply!

 

Glad to hear it is fixed. Thanks for the update to close the thread.