Hey guys, as a new member, let me first say I am glad to finally own a F body pontiac, as I've always admired them, even though I am primarily a mopar guy. I'm not that familiar with the common problems of these cars, and I just purchased a 1994 Firebird Formula LTI automatic from my late uncle's trust. I enjoy the car, and have only had it for one day, and now there is a problem. I accelerated hard from a stop light this morning with the "transmission perform" button pushed, which I'm sure is just a different computer setting for transmission shifts, but when I did, the drivetrain clunked several times through the gear, somewhat hard. Now, when I accelerate somewhat hard offline, there is a hard single clunk somewhere in the drivetrain, probably transmission to driveshaft area, and feels more on passenger side. When I accelerate very hard from a dead stop, now there is a almost high frequency vibration, or slight grinding coming from same area in first gear. Are there any known problems with these transmissions that you think could cause this. Any help would be appreciated, as GM is foreign to me. Thanks a lot, from one car guy to another.

 

Well since you're a Mopar guy I'll let you down easy...1994 is the fourth generation F-body. Not the third.

That being said, the clunk could just be the power transfer going through the suspension and such. I'm not too familiar with 4th gens so don't quote me on that. But check/change all your fluids and try to pinpoint exaclty when/where the clunk is coming from. It might even be a bad mount.