I had that same problem with my viper x2s burned up my spur gear. But i was having a tug of war with a tmaxx and just floored it tires started to spin then stopped moving should have realized something was wrong but i held the pedal to the floor (kinda stupid on my part but o well) needless to say i lost and had to replace my spur gear set up o well next time ill just throw a rock at his t maxx and break it [>:]