Ok i was out racing the other day and when we were lining are cars up i was too far ahead so i put it in reverse and backed up a bit well me being a dumb@$$ i forgot to put back into drive and when he said go i stopmed the the pedal and the reaend started hopping like a mother but didnt go any where so i layed off of it and put it in drive and it worked fine. I still have posi, it still shifts nice no problems except uh when its in park or neutral it acts fine but as soon as you put it in drive it starts vibrating like crazy and it does that from idle to about 3k then it acts normal but i know its broken somewhere
so what do you think it is. I thought maybe drive shaft or converter.

 

Sounds like a U-Joint to me.

 

I think everyone has done the same stupid thing before. I just so happened to do it at the track. I drove around the water box and then backed up to get in the burn out area. Did the reverse burnout and then felt stupid for the rest of the day.
Brandon

sounds like it could also be a tranny mount

 

My first bet would be the tranny mount as well. Sounds like the same symptoms I had when my was gone. Just go easy through the gears until you get it changed.

 

when my tranny mount broke it was fine other than when i started to accelerate and it sounded like everything in my engine bay was about to fall out...giant clunk every time the car moved....

 

Same here. Exactly as you put.

 

so u raced in reverse? :P

 

Good job! I told you R dosn't stand for RACE.

 

I take it u didn't win??? What type of car did u race?

I would say tranny mount too...I recommend a "Prothane" mount..

 

 

I'm not sure which would be worse... Doing that to your own car, or having to tell people what you did.

 

It was 98 Gt and the second time we raced i showed him who his daddy was but even though i beat him i feel like i got beat because of how laud he was laughing.

So you think it is the tranny mount, Why does it go away at higher rmps?

 

it happens to the best of us had a similar thing happen and i ended up with the worst exhaust leak ever Header shook it self loose from the Ypipe

 

Well,

Start from the easiest and cheapest on up

1) Visually check everything down there (u-joints, mounts, fuild leaks, driveshaft weights)
2) Feel for play in d/s and rear gears
3) Change tranny mount
4) Change u-joints
5) Change Driveshaft


If one step doesn't fix it, move to the next one