I have a scope that has a 16-3/4" Byers drive on it. I had to take it apart to move it, but I'm not sure it was set up right to begin with. I need an original set of instructions (or a copy) for setting it up, or someone to tell me just what I need to do. I have installed smaller worm drives before, but this is a rather big one and I don't want to take a chance of messing it up. If you can assist me, I can give you the details of the problem.