hi, totally new to the picked up my son a summit, without thinking of course, now running into some problems. WHen driving on gravel or sand and he is spinning and turning I hear a constant clicking noise. I thought it might be the servo and replaced the gears, however that did not solve it. When he's driving straight its fine, its when he's spinning and turning oh and braking I hear the noise. Any help is appreciated and if anyone has traxxas summit for dummies well that would make my day.