i have been slowly upgrading my amp crush since i bought it this summer. My ESC went out Fiday night and i decided to go ahead with the spektrum brushless motor combo from Hobby Town. i am afraid it is way to much power for the gearbox. i already had the metal differential upgrade, but yesterday afternoon as i was driving through the yard, that motor totally ate my spur gear. i do not see a specific metal spur gear for the amp and i was wondering what you guys did if anything?