What is your gearing, esc settings, motor can timing, an belt tension settings? When did you rebuild your diffs last? Are you running stock slipper or vts? When was the last time you checked your bearings through out the truck? The more info you give us the better.

Unfortunately, my X-12L 4.5 motor was disappointing and had temp issues as well. And I'm not the only other one. I switched brands of motors but kept my tc spec.