Originally posted by popsracer
Really it all depends on the Car and how dirty/dusty the conditions that you race on are. Many times a good cleaning and relube will fix the problem without replacing any parts. You should be able to turn the Diff Rings and Thrust washers over to a fresh side and maybe just replace the balls. (bearings)
On my HPI Pro-3, I can get about 2 weekends of racing before cleaning and relubing the diffs and I haven't had to replace any parts yet.
spot on. Depends on cars, really... My Schum Axis needs a rebuild every 20 packs or so, whereas my TC3's diffs stay smooth forever and ever... Several things actually matter: sealed or open tranny, dirty track, stock or mod, diff adjustment, parts quality...
Flipping diff rings is a good trick. Also note that it's very often the thrust bearing that's messed up rather than the main balls/rings... You can also sand diff rings with 1200 grade sandpaper, if you do it right you'll get a smooth finish which works perfect.
Anyways, if you want to purchase some steel balls, go to McMaster Carr's website (Easy to find). You can buy them by the hundred, and it's considerably less expensive than at your LHS.
So far the longest lasting I saw were AE's. Second longest were Losi's.