i have a 1988 firebird T/A with a v8 5.0L automatic engine and i have this problem that i cant seem to figure out. Awhile back in august when i first put the car on the road it wouldnt shift into reverse just once and since then it has been fine. lately though when i take off theres a hard knocking noise that kind of drags or "rolls" on if u really step on it. the sound is underneath the passengers seat and foot area. also when ur already going like 55 and u push the gas u can make it make a little knock over there. So im not sure if its maybe the motor mount or something like that but i would appreciate it if someone could point me in a direction so then i can get this problem fixed and start accelerating like i really want to without feeling im hurting my car thanks
email

 

Sounds like maybe the tranny mount. Mine was split in half on my old V6, but it never "dragged". I would hit the gas hard from a stop and get a THUNK from the tranny area but it was quick. Worth taking a look. Stock rubber type around me when I replaced mine was $3, so it wasn't a big deal money wise. Just getting the rusty old bolts off was the challenge.