Howdy all, here is part 2 of how to understand and adjust your GDO. Now that you have decided you are comfortable with working on a ladder and working overhead and checked the doorbalance and hardware and adjusted the forces---all as outlined in part one...we can proceed.

Lets look at how to adjust the limits. NORMALLY this happens after the force adjustment if you dont have broken internals and is very simple. But for completeness let us first assume you have done the worst things like changed a chain or gearkit the wrong way and now the limits are not even close to being in the proper position.

Manually close door. UNPLUG and pull cover. Make sure you have pulled the trolley release so chain moving wont move the door. plug back in. WITH REMOTE THAT WORKS AT THE READY push the remote button to operate the door and watch inner trolley connected to chain. If it moves towards the closed position let it go until the GDO stops by itself.....EXCEPT if the trolley is with within a few inches of the end of the rail and still hasn't stopped stop it with the remote button. When the inner trolley is stopped in the down position like this the inner trolley should be about lined up with the outer trolley that is linked to the door. If it aint you can either: Adjust the down limit towards more travel if you only need a few inches of adjustment. If you are way off-UNPLUG unit, loosen chain and reinst chain so that the inner trolley is within an inch or two of the outer trolley. Now replug and hit the button again. The inner trolley should move up and stop about halfway on the rail for one piece, about 6 inches from the end of the rail for sectionals(most). Open door by hand, the inner and outer trolleys hould be within a few inches of each other. If not, adjust the up limit screw until the trolley parts align with each other. Now if you have a one piece move the up limit adjustment towards decrease tracel about 1 to 2 turns. With trolleys still disconnected run the gdo again, which should be the down direction; and close the door by hand.

The trolleys should be in the same spot. Now hit button and move the inner trolley up and manually open the door. Trolleys should meet in the same spot. If not adjust the up limit screw until they do. Now connect the trolleys, cycle the door and it should stop in the proper positions up and down. Next post we will check the safeties and the post after that some common repairs. HTH Dave.