I was having lots of problems with my diffs early in the spring, went through 4 of them till i got fed up and decided to do something about it. The 13t bevel gear was always loosing a tooth or 2 and ripping the rest apart. These solved all my problems http://cgi.ebay.ca/HPI-Savage-Alloy-...QQcmdZViewItem
I know you can find a cheaper set but IMO these are worth the money because they aren't made of 6061 alloy and the nova brand is known for quality.