Do you bearings spin smooth? Does the normally spin out to one side all the time? When the tires are off the ground, and you give it gas, do the wheels shake immensly? If so, you might want to consider a tire balancer. got the Dubro prop/wheel balancer and lead tape to balance the tires and my buggy is alot smoother and more consistent now. What motor are you running in the Evader? Put AE black grease in the thrust and AE diff grease in the actual gears. If your not running an extremely fast motor, loosen the diff screw about 1/2 a turn and see what happens. You want to get it kinda loose, but if the diff barks, TIGHTEN it to the place you had it before as it flat spots the diff balls. Is the diff smooth? Packing it is fine, as long as you wipe the excess grease that comes out from the outdrive.