Originally Posted by madbeats

Posted by Curve Tracer
I have not damaged a diff ... yet, but when building two of them this is what I have done.
1. Assemble the diff (without packing lube) to determine if the gears mesh ok. What I mean is that the parts turn easily by hand. What I have done is substitute the rubber o-ring with one from the shock kit. The combination of these blue/red rubber rings is what I use to set the internal gear mesh. Though it is a pain to assemble and disassemble the diff, it has worked for me.
2. When installing the tapping screws make sure the holes are free of
diff grease (easier said than done) and try a plastic friendly thread locker.

These diff's are not as smooth as my Kyosho GTR car, but the key is to set them up so that there is positive contact (by feeling the operation when it is assembled) but no binding while turning the parts when assembled.[B]