its not all out everytime you run youll blow a pinion, where the problems seem to lie is taking a jump and landing with the throttle or brakes on, or a good head on collision likes to take them out also. from my expierience anyways. just remember they are a flat out basher. they take alot of abuse and are probably given more abuse cause its whats expected of them but they are deffinetly not industructable by any means....