check the up and down adjustments on the head. Did you have a major rain storm lately, was it recently humid? This may have some effect on the system. Also check the balance of your door. You do this buy disconnecting the GRO and open the door a foot or so. It should stay in any position you leave it in (should not go up or down by itself). If the door is not balanced then maybe it is putting more strain on the GR motor and the gear may be going bad. However, if your door is really old, you may want to get a new unit. You could buy one on sale (craftsman) for about $129 and up and they will have all the updated goodies such as the secure transmitters, newer rails etc.