So after alot of time and money spent on my brothers volcano S30 it was finally working again! he had a bad crash last year and since its been problem after problem and after finally eliminating all the problems one by one it worked again! but now it has stopped, and i think the diffs are shot but im not sure, i took apart the whole front assembly and i put the driveshaft in and tried to spin it myself, the cup spins, so does the gear when i look at the inside of the diff but the wheels dont spin much, and when its on the ground the driveshaft just spins the wheels dont move, this happens with the front and rear diffs, are they shot?

either the diffs are shot, or the slug screw on the drive cups is loose allowing the cups to slip on the input shaft.

those are really the only 2 things...the slug screw is loose or the diff pinion/ring gear is stripped. If its stripped....you can usually hear it grinding/slipping.

Nawh its not the grub screw, first thing i checked, and i do hear grinding, can i just replace the pinoin gear or do i have to change the entire diff?

you can do it however you want.

You can buy just the ring and pinion gears...02029 and 02030
Or buy the pinion gear and the diff with ring gear on it...02024
And lastly there is an upgraded diff with ring gear....02024T

Hey thanks alot for your help! ill get those parts today hopefully because i have a redcat dealer 5 mins from my house all the parts i need and such
how can i stop this from happening again though? cuz it was just normal use lol