How to Fix your Rearend "Clunk"
 

http://www.maxcooper.com/rx7/how-to/...lls/index.html This is a great write up on how to change out your pillowball bushings to get rid of the clunk in your rearend.

Rearend clunk is normally caused by pillowball bushings going bad. You can get them from the Mazda dealer, part number is FD01-26-220. Sometimes the rear differential bushings go bad as well causing the driveline to feel sloppy. You can buy these from numerous other places/vendors. Feel free to chime in with your experience.

Let’s not forget the rubber seals:
FD01-26-250 X 12

And just in case you loose one, the c-clips:
9957-43-800


Dan

For differential gear noise and just good protection, AMSOIL now makes several sevear gear oils that are tested (if you trust them) to be great. I am trying the new 75w-110.
Price is slightly more expensive than REDLINES 75w-90.