Sprocket is at the end of the opener rail closest to the garage door opening.
Garage door chain drive fix.
A new front sprocket costs about 150 200 include the labor to install it.
Located along the rail the chain an.
Start by checking the things below to see if it is the problem lies with the garage door.
The chain wraps around this sprocket as well as the gear and sprocket at the motor.
If the motor hums but the chain doesn t move that indicates a problem with the motor.
If you are not confident in your ability to diagnose the problem call a local garage door service company.
This video from sears partsdirect shows how to replace the chain and cable assembly on a chain drive garage door opener.
Tighten the bolts on.
If there are some you can use a wood block and your hammer to fix the dents.
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.