I know its not my assembly because you cant assemble the diff backwards. Plus I have lubed the back one and had it apart twice as many times as the front...and its still fine...I didnt forget to re-shim, I put the factory shims back in EXACTLY where they came from and checked for play/binding after assembly.

Upon further thought I think it may be my driving. I'm getting pretty good with technical stuff but I have been going from flat out 2nd gear to full wheel lock, sliding into a corner and then full throttle out of the corner....over and over again! I figured the FF could take this abuse but I guess not. I think MAYBE what happened was those 3 screws sheared off from being pounded on so much...once they broke all it took was a little time for the rest of the parts to go.

Then again...I think I have a lemon. I had a broken connecting rod earlier after only a gallon...and I was SO taking care of the engine. I followed Cen's nitro "Handbook" to the letter.

Good to hear at least I'm not the only one this has happened to!