94 Buick Roadmaser rear end shudder, won't shift .Just did rear end at shop.
Picked it up from shop, drove < 6 mi. rear end began shuddering and wouldn't shift when trying to accelerate past 40 on freeway merge. Car began slowing down, I got it to side of road. Did shop forget fluid?
Who knows, it’s going to have to be towed back there to find out what they did wrong.
I agree the shop that did the work needs to fix the issue and pay for your tow. Sound like they did not (possibly) tighten up the u joint or its not seated in its mount correctly and is causing an "out of balance" situation. Good luck and let the shop fix their mistake. (good shop will test drive a car before giving it back to the customer)