Help...truggy doesn't go...

[Big House]

As far as I can see there are no binding points in the drive train to de seen. Like I said, I rebuilt all three diffs; new grease, new ring and pinions...no drive issues. Off the ground...it make pizza cutters on each corner but on the ground, under throttle the center diff spins but does not drive the rear and barely musters the fronts. I will get some video of it in action tomorrow.