I have a Liftmaster GDO that is now 12 years old. I have had no problems with it - yet. I notice the chain is sagging about 2.5 - 3 inches below the rails when closed. It is also "less smooth" in opening and closing. I have used the tensioner bolt to make it as tight as possible - but that is the best it will do. Does anyone know how or if links can be removed from the chain. It isn't intuitively obvious to me how but I am guessing it can be done.