When driving my 1991 Trans Am 305tpi, the car makes this loud thump, when accelerating from a stop. It is sounds like something is smashing into the bottom of the car. Any suggestions?


Asked by Sep 16, 2012 at 12:47 AM

Question type: General

7 Answers


when was your transmission fluid changed? esp if it was an automatic. clutch pack could be slipping.


also, check mounts.. engine & tranny should not move much. 1" is acceptable.


car is automatic, mounts are good, transmission fluid was changed recently. car has a total of 138,000 miles.


Transmission mount on cross member(at tail shaft) is probably bad. It may look ok but I would remove and inspect. Very easy to do. They are known for going bad. Good luck


hahaha.. I know that sound all too well.. You broke your transmission mount. You will need to change it.. I used to break mine all the time. Put too many people (weight mostly) in it.. And it will break it..


That's the funny thing, I never have anyone in the car other than myself, and one passenger, but thank you all for the answers.


Yeah.. I was mostly speaking on myself with the passenger load thing.. I had an 85 camaro and an 89 GTA trans am. Funny thing with those cars is that the passenger weight is like 450lbs. Two normal sized guys and a speaker box in the back pretty much taps out the max weight. And that is on a new mount driving like an old lady (no offense meant). I ended up putting a poly trans mount and it solved the problem of breaking the mount.

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