Examine the metal tracks on the door for dents or bumps.
Garage door chain drive fix.
Sprocket is at the end of the opener rail closest to the garage door opening.
A new front sprocket costs about 150 200 include the labor to install it.
If the motor hums but the chain doesn t move that indicates a problem with the motor.
This video from sears partsdirect shows how to replace the chain and cable assembly on a chain drive garage door opener.
Located along the rail the chain an.
The chain wraps around this sprocket as well as the gear and sprocket at the motor.
Make sure the tracks are aligned properly.
Press the remote or the wall mounted start switch listen to the motor and watch the movement of the chain.
If you are not confident in your ability to diagnose the problem call a local garage door service company.
Slide the pulley toward the garage door until the chain is stretched tight then move it toward the motor until the middle of the chain touches the upper side of the chain arm.