Hey dudes. My car has a loud thump when I get on it pretty good going from first to second gear. It's a 4L60E. I'm not sure which one is the cause, but I am assuming the transmission mounts rather than the TA bushing. Any recommendations on brands? I was considering going with a stock LS1 trans mount, I heard they hold up well without the vibration of the polyurethanes. I have heard mixed reviews about the poly trans mounts, but some say its no problem if you leave the plate off that comes with the mount. I was looking into an Energy, Prothane, or GM Performance mount from Jeg's/Summit. Any recommendations, experiences, tips, etc. that would make swapping the mount/bushing out easier?

 

while you're down there with it all apart....swap out both.

the TA bushing is much easier when you drop the trans crossmember.

as for the mount....my ES poly unit works fine, minimal vibration. but then again i have poly motor, trans, TA and suspension mounts...