Garage Door Chain Sprocket Broke

The gear and sprocket assembly is inside the cover of the garage door opener motor.

Garage door chain sprocket broke.

You can put the chain back on your automatic garage door opener using a simple adjustment mechanism. Over time though this slack can increase or the gear and sprocket assembly can wear and the chain may pop off the sprockets. The most common cause of a chain being loose and appearing broken is a broken gear and sprocket. This is the part that connects the motor to the chain or belt.

It wasn t listed for the same model but after looking online it seems that most garage door openers made after 1984 use the same sprocket assembly. One of the most common repairs on a liftmaster garage door opener is a broken gear sprocket. Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door. This was a craftsman model 139 53976srt.

This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener. Chain driven garage door openers should have some slack in the chain for optimal performance. It was a perfect replacement and the garage door is working. Chain drive garage door openers have a sprocket that is attached at the top of the motor.

Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door. The bag said it was an oem piece. This is a video on how to change the gear sprockets in a craftsman garage door opener. Your garage door opener has a gear and sprocket that will eventually fail.

This can be easily replaced by a garage door service technician. If the gear and sprocket assembly breaks the motor runs but the door won t move.