[quote]ORIGINAL: monsterbombs

you can adjust a normal traxxas gear diff with different oils, no?
a ball diff is definatly an upgrade for a racer as you can tune it
without pulling apart anything (pop a driveshaft out thats all).

The traxxas diffs are not sealed so they cannot be tuned with different oils.. You can mod them to be sealed its not hard to do.. basically they leak at the bearings so you have to get a oring seated in there to seal it.. and some silicone around the case..

I've looked at the ball diffs for the rustler, but they are not worth the money.. if you are a serious racer maybe, but for bashing no.. the traxxas diffs work fine the way they are, but could use some adjustability.. I will be doing that mod over the winter months..