I want to stop replacing tranny mounts. Here's how many I've replaced:

1) Stock one broke, replaced with ES and pre-load (spacer plate). Had fun removing stripped tranny bolts. Thunking noises during launch from the beginning, broke after couple thousand miles. Tranny crossmember bolt hole that ties the mount to cross-member was seriously worn down and enlarged.

2) Replaced with new ES, no pre-load plate. Never broke, but made irritating squeeks/groan over speedbumps/bumps. New tranny cross-member, no significant wear marks.

3) Replaced with rubber stock mount, broke after thousand miles.

4) Prothane tranny mount, along with poly tranny mount. Quiet for 2 days, now makes the same squeek over speedbumps, occasional thunk from underneath.

Couple of driving observations: it sounds like there's bind during braking. Seems like the tranny moves up and down over speedbumps or bumps in the road.

What could be causing these mounts to break. Broken engine mounts, how would I check for this? Car has never been in an accident.

 

could be motor mounts. Jack the motor up slightly and do a visual on the mounts. (motor).