need better diff for rustler.

[lincpimp]

If you are having issues with the internal gears the al cased diff will not help. I am not sure what to suggest, the new traxxas batch of gears are too brittle. I used some really old internals, the gears we shinny, not black like the newer ones. Since then the diff has held up just fine. I also tried the al cased diff and it made no difference. Maybe a call to traxxas is in order?!