How do I replace the sprocket coupling sleeve on a 139-53663SRT 1/2 hp garage door opener?

HVAC & Fireplace Bucket EXPERT June 17, 2008

Reading through the assembly procedure in the Owner's Manual and looking at the parts illustrations there or at Sears PartsDirect will help give you an idea how the procedure will need to go. See images below for more.

Since the ends of the motor output and the rail screw drive go into either end of the coupling, you need to move the motor unit and the rail apart to get the coupling out. You can remove the motor unit completely by reversing the install instructions, but often you can gain enough room by just loosening both the rail mounts and the motor assembly mounts slightly. Once the mounts are all loosened you can often move the motor unit and rail far enough apart to get the coupling sleeve out without actually removing either component.

That means you do not need the extra people and assemblies to hold up the motor and rail and you can also spend less time realigning them after you replace the coupling, just take care that you so not loosen the motor or rail mounts too much or they could fall.

The coupler itself should come off the shafts fairly easily once there is enough room for it to move.