Do this...<div>
</div><div>Hold the center diff still and roll the REAR wheels only. Do the fronts turn in the opposite direction? Try the opposite (roll fronts with rear off the ground). Does it seem smooth?</div><div>
</div><div>Lift up the front of the car, and turn the motor pinion or spur gear by hand with the rear wheels on the ground. The fronts should rotate forward very slowly. To be honest, from what you said (though you really should try to explain better) it sounds like there is a problem with the ring and pinion at the front diff, but it could be anything really. If you have the ability to make a vid to show better what the problem is, that will help.</div>