andy91rs

Yesterday, my car stared thumping hard under full acceleration. During normal acceleration, the car shifts fine and makes no noise and thumps. My father seems to think that one of the transmission mounts or engine mounts are loose or off, and when the car gets hard torque it jerks the transmission up and hits the car. I was wodering what you guys thinks. If you need any more information to tell what the problem is, post it and i will get the answer back soon.

Thanks for your help.

FruityOne

That definitely sounds like a tranny mount. I had the unfortunate experience as well. Seeing as how I only drove FWD cars before my GTA I'd never experienced it. Not fun, I thought I did something nasty to the car.

DO NOT get on the throttle until you change it. A stock rubber tranny mount is a $10 part at autozone I think. A Polyeurethane mount won't break, but it doesn't provide as much damping as a rubber mount. Hence more noise and more vibration.

You should be able to change it within an hour, half of the time spent jacking the car up and aligning the mount. Its a total of 7 bolts in all to change it. If you've never done it make sure to support the tranny with a jack and some nice padding(like a 2x4 block) to spread the load, otherwise you could dent or deform the tranny pan.

I'm sure that someone who is much more knowledgable will come along and help with this. If your father is guessing what it is then chances are he's changed one before, or had one break.

MdFormula350

O yeah, sounds just like my old formula did, i had that and wheel hop during a launch in first gear.

http://www.spohn.net/index.cfm?fusea...t&productid=90

a poly tranny mount is like 26 bucks, i would buy a poly one so it doesnt happen any time soon again.

but a new rubber one will do you fine for awhile.


Another Marylander thats cool, check out these links.

https://www.thirdgen.org/techbb2/for...?s=&forumid=50

https://www.thirdgen.org/techbb2/for...?s=&forumid=42

90firebird

i had the same problem, and had a guy i know slap a polyurethane tranny mount for me. he owns his own garage, so it didnt take him very long. he used one jack to lift the car from one side and another under the driveshaft near the tranny (i believe it was the driveshaft, it was a long time ago) to support everything. he used air tools, and it took him only like ten mins... so i cant tell you how long it will take you.
you will experience some vibration from the polyurethane mount if you choose to use it, but its not a big problem.... its not noticeable if you ignore it.

andy91rs

thanks for the help. We finally got the car in the air to look at the mount. The rubber is torn just like my father and all you guys said. I dont have time to put the new one on till tomorrow but I will tell you how it worked out. Thanks for all your help.

andy91rs

I got the mount fixed and it runs perfect now. Thanks for all the help.

FruityOne

Just an update to the thread, I finally got my tranny swapped and the poly mount in there. I am VERY happy with my ES poly mount. When people told me to expect a little more noise, and vibration but its piddles compared to the benefits of my poly mount. I should never have to change it again if ES is right. Thats if I don't do some serious powering up though.