Graphite
 

Ok, heres the deal, i think the reason these xmods are so loud is the gears hitting together like hte stupid zz wannabe's so what would it hurt to put graphite on the motors' gears' and use in the awd kit instead of the grease it comes with that slows it down instead of pseeds it up

I don't see a reason not to try it, except that it's a pain in the ass to get off if you decide you don't like it.

Or use white teflon dry powder usually available in LHS where they have railraod lubes