Nope buddy, don't think it's the esc. Did find out the problem. It's a loose screw in e diff. Threadlock was not strong enough. Anyway am facing a dilemma now, after putting all e diff back with the housing, the diff seems to lock or seem to be very hard when I tighten the bottom 2 screws and the top 2 screws that house the diff. But then I tighten e screws to wear both covers meet n form properly. So is the diff some to be freewheeling or is it suppose to be tight?