Garage Door Chain Sprocket Broke

This is the part that connects the motor to the chain or belt.

Garage door chain sprocket broke.

Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door. This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener. It was a perfect replacement and the garage door is working. This can be easily replaced by a garage door service technician.

This gear set worked great and replaced a broken one in my 2002 1 2 hp chamberlain liftmaster yesterday. Chain driven garage door openers should have some slack in the chain for optimal performance. Over time though this slack can increase or the gear and sprocket assembly can wear and the chain may pop off the sprockets. Liftmaster and chamberlain garage door openers are very common for this.

If the gear and sprocket assembly breaks the motor runs but the door won t move. One of the most common repairs on a liftmaster garage door opener is a broken gear sprocket. This was a craftsman model 139 53976srt. You can put the chain back on your automatic garage door opener using a simple adjustment mechanism.

Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door. This is a video on how to change the gear sprockets in a craftsman garage door opener. Chain drive garage door openers have a sprocket that is attached at the top of the motor. After several years the garage door springs become weaker causing more stress on this particular part causing it to fail and wear out.

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