I have developed the popping in the driver door hinge so I went to tighten everything and it was all tight except for one of the bolts on the lower hinge attaching the hinge to the door. One of these bolts just turns continuously in the door. Is there a bolt on the inside of the door or is the hole threaded for the bolt? The other bolt there is good and tight but I can't get the other to go in or out, just turns. Help.