Good points yakfish, but 1.) brushless will also destroy diffs and drivetrains - even moreso.., and 2.) Losi diffs a.) are very, very tough and reliable, and never need work, and 2.) they are actually extremely accessible.. Just did one last weekend.. Was surprised how easy it was to get out...(Gears and housings and everything were fine btw.. Just two years old, so the bearings needed replacing... )