I just got my transmission totally redone with converter. When I got it back I noticed that it kind of clunks during shifts, almost feels like bad motor mounts. But the one that worries me the most is when I'm decelerating and right about to stop, I think it is the 2-1 downshift, I hear a loud clunk sound coming from the rear. This never happened before I got the tranny done. I changed the tranny mount and it still does it, I'm pretty sure the motor mounts are bad, but they have been bad for a long time and the car never clunked like that. Because of the tranny job it does shift alot firmer, but I don't think its firm enough to clunk the way it does.
Any help greatly appreciated.
Sounds like the u joints or something related to the driveshaft maybe. Chock the wheels good and leave it out of park and crawl underneath and twist that shaft in both directions with fast transitions from left to right and see if you can duplicate that sound. Maybe they did not tighten the u joints all the way down. I am not a pro but happened to me once this way. Oh yeah also heard something like this when I had tv cable way out of adjustment. Just my 2 cents...
How exactly do I inspect that? What should I look for?
Look for play at the ends of the shaft where the u joints are held in place by 4 bolts with u shaped clamps holding them in . Check both of these connections front and rear. It could be u joints not 100% sure of course but any clunking coming from tail end of tranny interior sounds like a trip back to the guy who did it. Did you try asking him?? Maybe swing by let him lift it and take a look? Peace.