When shifting into any gear I get a bad "thumping" noise from the rear-end of my car. Some have told me it's probably a broken front diff. mount. I don't know if it's the front of the differential "knocking" or not. I guess I'll just drop my rear subframe and figure it out. I was kind of seeing if anyone else has run into this problem before and could possibly tell me what they had found.

 

Diff mount. Its happened with every rx-7 ive ever owned.

 

i installed a pinion snubber, solved mine. Also stopped my wheel hop.

 

yeah see I have REALLY bad wheel hop when I take off from a dead stop..

is that the diff mount or what?

I deffinatly think the diff mount is cauing your slapping problem

 

you're on the right track. Check the front diff mount. That solved MY thumpin noise.