Garage Door Chain Sprocket Broke

If the gear and sprocket assembly breaks the motor runs but the door won t move.

Garage door chain sprocket broke.

One of the most common repairs on a liftmaster garage door opener is a broken gear sprocket. The chain got loose and popped off the gear. After several years the garage door springs become weaker causing more stress on this particular part causing it to fail and wear out. Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door.

Chain driven garage door openers should have some slack in the chain for optimal performance. You can put the chain back on your automatic garage door opener using a simple adjustment mechanism. I am not a professional. Documenting how i repaired the garage door.

Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door. Liftmaster and chamberlain garage door openers are very common for this. Chain drive garage door openers have a sprocket that is attached at the top of the motor. The gear and sprocket assembly is inside the cover of the garage door opener motor.

This is a video on how to change the gear sprockets in a craftsman garage door opener. This was a craftsman model 139 53976srt. The most common cause of a chain being loose and appearing broken is a broken gear and sprocket. Your garage door opener has a gear and sprocket that will eventually fail.

This can be easily replaced by a garage door service technician.