I have recently completed the swap from 700R4 to T-5 and have yet another question. Has anyone who done this experienced any unusual vibrations? The car is equiped as follows:

T-5 out of 89 T/A
Flywheel out of 92 (RS I believe)(25lbs)
Centerforce clutch
Poly torque arm bushing and tranny mount
Car is 89 IROC w/ 350 TPI engine (48K miles)

The vibration really shows itself between 2500 and 3500 rpm. It is not bad enough to concern me but it's there. Is this normal with the clutch? Any info or comments are appreciated.

 

I don't know if it has anything to do with this or not, but a while back some guys were having problems with the poly trans bushings being too tall or something. Don't remember what the symptoms were, but it might be worth checking the archives.

 

I'm not an expert but I was told by one that the countergear stabilizer bushing and the tailshaft bering are very weak points in these trannys. Pull thr driveshaft and check the tailshaft shake it back and forth check for play could be the bering. mine sounded like it was grinding rocks and I found the tailshaft bering was wiped, lots of play lots of vibration

 

Thanks for the responses so far. I had checked the tailshaft prior to install and it was OK. I'll keep an eye on it though.

The mount was not putting the tranny against anything and the poly mount was the same height as the original. Is it possible that just being a harder mount is transmitting that much more vibration?

This noise is there with or without the foot on the clutch and/or it in gear. I just don't want to be ignoring a potential problem.

 

How bad is the vibrating?...shaking the whole car or just something noticeable?.....

 

For the most part it is just noticable. It vibrates enough to slightly vibrate the rear view miror but thats as bad as it gets. Only noticable really between 2500 and 3500 rpm. I'm starting to think it is the poly bushing as I had the old half wasted rubber one with the auto. Any ideas?