Replacing a garage door opener gear is not a difficult project, but does require some care and attention to detail. This gear is situated between the belt and the motor drive.
Step 1 - Unplug Opener
Before doing any work on the garage door opener you must unplug the opener to guard against the possibility of an accident.
Step 2 - Disconnect Top Rail
In order to get at the gear you will need to disconnect the top rail from the front mounting bracket. Once the bolt is removed, lower the top rail towards the floor. You may rest it on a cart, or ladder rung.
Step 3 - Remove Front Cover
With a screwdriver, remove the front cover of the garage door opener. Once the cover is removed, take out the light bulb. The panel in behind the light bulb will also need to be removed to get at the garage door opener gear.
Step 4 - Disconnect Belt and Gear
Release the tension on the belt with the small lever near the gear. Press this lever and you will be able to remove the belt from the gear and pulley. Push the pin in with a nail set in order to remove the gear.
Step 5 - Replace Garage Door Opener Gear
Set the new gear in place and secure with the metal pin. Re-install each of the components in the reverse order and plug garage door opener in.