I just recently put a some RPM parts on my Slash 4x4 and I figured since I had the tools outs and it's the middle of winter that I take the bearings out and clean all of them and get the truck ready for when middler weather shows up. But after I put her all back together i was spinning the rear wheels manually and the front wheels where not spinning and when spinning the front wheels the rear wheels would not spin? And what I don't understand is that everything was working find before i started working on it.