SO, I put in an energy suspension tranny mounts (polyurethane) and I noticed that the mount is rougly .25"-.50" taller than the stock GM one. I remember this happening in my 84 Z and my 87 Z. Is this a bad thing and could it lend to the greater feeling of vibration?? I know the rest of my drivetrain is good. I have 33K original miles on my 1LE now, perfectly balanced aluminum driveshaft and have never done anything to bend the frame or cause vibration. I know poly mounts of any kind will normally enhance the vibrations a bit. Just wondering if you guys have noticed the height difference and if that would do any harm.

 

Believe it or not, it's the same height as a stock one before the blob of spooge in the middle of it gets mashed flat from being such a POS.

The stiffer mount does transmit a bit more of the natural vibration to the chassis.

If you put the shim plate in, take it out. I've never seen a situatio where it was required. Maybe it is in some other chassis (it fits all GM RWD cars) but not in these cars anyway.

 

I used the shim plate on mine when I installed it in '97, never noticed any extra vibrations with the ES mount & shim. I don't think the shim's needed either, but the instructions said to use it, so I did. I even have the ES torque arm mount, and didn't notice any extra vibrations. If they're there, they're so minimal that you'd probably need to have a very sensitive seat to notice!