muscle, when you spin over 30 mph, the TC will over-ride...it was on...keeping your tires cool when stuck, and rocking back and forth gradually will usually get you rolling...spinning getting them hot, just lets you burn down to pavement, but kills your tread, and can damage the drive line...its a ***** to get stuck, but patience should prevail...I've proved this to my sons many times...I agree with the other, snow in the wheels throws them out of balance...pray for spring....