I have a 8 year old GDO. It stopped working today. The motor is running, but a plastic bearing (about 2 inch in diameter, and it is vertical) is worn out. A lot of plastic crumbs inside the box. I went to Sears, and was told that the bearing is a cheap part but difficult to replace since I have to use special tools to take off the pins on it. The salesman suggested buying a new GDO, but I have to replace the whole thing including the rail (I have the old reversed T-shaped one). That is also a lot of work and will cost me over 100 bucks. I wonder if anyone has replaced that plastic wheel (it is a frequent problem according the salesman), and how? Or, it is a good idea just to replace the whole thing? Many thanks.