Tony: You ever try White Lightening on the diff gears? Is the Losi White grease the stuff they put on the diffs or on the thrust bearings>
eBoi: Check the pinion to spur mesh. If its too far apart the gears make a lot of racket.
cantbestopped44: If you're just starting out, get the TC3. Any of the belt drives that don't have sealed drive trains are trouble waiting to happen in the street or parking lot. You'll spend a lot less time turning wrenches with the TC3 than with the T1. AE parts are easy to get - try getting a T1 (or Yokomo) belt from your LHS on a Saturday night before Sunday's races. Save the extra bucks that you'd spend on the factory kit and buy yourself a decent FM radio. Like Modena says, get the Novak.
By the way, belts suck.