From your second post it sounds like you have removed the front ds so if you have it in neutral and the rear either disconnected or the rear tires off the ground you should be able to turn the rear ds with your hands. Sounds like something is wrong inside, don't know what it may be but it should be looked into. Could even lock up which if you were driving it may not end well for you. In neutral the fact that it is attached to a motor is not a factor and if there is still a tcase that would not be a factor either.
