Garage Door Opener Sprocket Broke Off

This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener.

Garage door opener sprocket broke off.

Over time though this slack can increase or the gear and sprocket assembly can wear and the chain may pop off the sprockets. This gives the appearance of a broken chain or belt. Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door. Chain drive garage door openers have a sprocket that is attached at the top of the motor.

Chain driven garage door openers should have some slack in the chain for optimal performance. If the gear and sprocket assembly breaks the motor runs but the door won t move. A new front sprocket costs about 150 200 include the labor to install it. If you are not confident in your ability to diagnose the problem call a local garage door service company.

The chain wraps around this sprocket as well as the gear and sprocket at the motor. One of the most common repairs on a liftmaster garage door opener is a broken gear sprocket. This was a craftsman model 139 53976srt. Sprocket is at the end of the opener rail closest to the garage door opening.

You can put the chain back on your automatic garage door opener using a simple adjustment mechanism. Eventually this will cause the sprocket to snap off. After several years the garage door springs become weaker causing more stress on.