This was a craftsman model 139 53976srt.
How to change garage door opener gear and sproket assembly.
Replacement gear and sprocket assembly compatible with chamberlain estate series chain drive garage door openers.
Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door.
041c4220a is a complete chain drive gear and sprocket replacement kit.
If you replace the sprocket assembly in your chain drive garage door opener yourself you may be able to save a lot of money.
The process isn t as hard as you may think so consider the guide below.
Disconnect the power cord from your door opener before doing any kind of repair.
This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener.
Compatible with chamberlain models pd752 pd758s pd752d pd758d all models may not be listed.
If the gear and sprocket assembly breaks the motor runs but the door won t move.
This is a video on how to change the gear sprockets in a craftsman garage door opener.