Make sure the tracks are aligned properly.
Garage door chain drive fix.
Located along the rail the chain an.
This video from sears partsdirect shows how to replace the chain and cable assembly on a chain drive garage door opener.
Press the remote or the wall mounted start switch listen to the motor and watch the movement of the chain.
If there are some you can use a wood block and your hammer to fix the dents.
A new front sprocket costs about 150 200 include the labor to install it.
Start by checking the things below to see if it is the problem lies with the garage door.
Examine the metal tracks on the door for dents or bumps.
Tighten the bolts on.
Sprocket is at the end of the opener rail closest to the garage door opening.
If you are not confident in your ability to diagnose the problem call a local garage door service company.