One of the last steps in the center diff installation is putting the slipper clutch nut back on and making sure the spur gear still spins slightly when the other end is held still...unfortunately my spur gear will not move at all even if i loosen the nut up completely. My question, is the spur gear SUPPOSED to be able to move when the center diff is installed? Just wondering if I installed something wrong (not sure how that would be possible, but you never know with me, )