Weird thing happened to me over the weekend. I was replacing my old rubber tranny mount with a Protane mount I got from thunderracing... while Installing tightening the middle bolt (the one that bolts to the crossmember) I suddenly feel my hand hit the car as I broke the screw and the bolt goes flying... how can I trust this mount to hold when I wouldn't even take my arm's strenght? Lucky it comes with 2 screws and 2 bolts and I was able to install it.... My hand still hurts

 

BTW, the vibration is now CRAZY! Lots of vibration now

 

Those hard tranny mounts will do the vib thing.

 

Sounds like you were over-torquing the nut. Anyways, plenty of people complain about serious vibes after doing the poly u tranny mount, that is why I went with the LS1 mount. Good and strong; no vibes

 

After I put my poly tranny mount on the crossmember was a very tight fit, had to go slow on both sides and ratchet the whole thing tight, but I think it's pretty nice overall. If there's a lot of vibration, I can't notice it, probably because the shifter was "jiggling" with the stock mount, I guess it was on it's last legs. I'll be putting in poly motor mounts next, I don't enjoy watching the shifter move when I gas the engine in neutral. Better to have a little vibration than to have your trans bouncing allover the place if a stocker lets go.

 

LS1 Tranny Mount