I get a weird vibratioon around 2500-3000rpm ever since i tossed in my new tranny mount,what could it be.I put it in right.except for the vibration the shifts fell much better

 

Did you do this in conjunction with fresh motor mounts ?

If not you may have changed the pinion angle enough
to induce a driveline vibration....

Check your pinion angle...

If it is pretty mild it could be some driveline vibration
that was always there that is now magnified

In that case still check the pinion angle but also
have the driveshaft balanced.

 

I recently read on another board that the poly tranny mount is 1/4" too high. This causes pinion angle problems and vibration.

 

All of the ones I have looked at were the same size
as a stock replacement unit. However as the stock
motor mount / tranny mount system ages they sag.
Roughly in equal amounts give or take a bit.

Changing motor mounts is a pain but its just "work"
Nothing clever or interesting about it.

 

hey bro same problem here..original mount was toast..so went with new poly unit..low and behold..vibration..out the ying yang...went back to orig rubber mount,,much much better but still have some vibration..looking at the drive shaft now with glaring eyes..lol..later bro