This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener.
Garage door chain sprocket replacement.
This was a craftsman model 139 53976srt.
Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door.
The process isn t as hard as you may think so consider the guide below.
If you replace the sprocket assembly in your chain drive garage door opener yourself you may be able to save a lot of money.
Chain drive garage door openers have a sprocket that is attached at the top of the motor.
Step 1 turn off the power.
If the gear and sprocket assembly breaks the motor runs but the door won t move.