Garage Door Opener Sprocket Broke Off

This is a video on how to change the gear sprockets in a craftsman garage door opener.

Garage door opener sprocket broke off. Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door. Chain drive garage door openers have a sprocket that is attached at the top of the motor. Over time though this slack can increase or the gear and sprocket assembly can wear and the chain may pop off the sprockets. 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. The chain wraps around this sprocket as well as the gear and sprocket at the motor. Chain driven garage door openers should have some slack in the chain for optimal performance. Sprocket is at the end of the opener rail closest to the garage door opening.

This gives the appearance of a broken chain or belt. After several years the garage door springs become weaker causing more stress on. One of the most common repairs on a liftmaster garage door opener is a broken gear sprocket. Eventually this will cause the sprocket to snap off.

If you are not confident in your ability to diagnose the problem call a local garage door service company. A new front sprocket costs about 150 200 include the labor to install it. You can put the chain back on your automatic garage door opener using a simple adjustment mechanism.