Replace the main gear drive if the garage door opener makes a grinding noise but the door doesn t move your main drive gear is probably toast.
How to repair garage door opener chain.
Garage door opener won t open all the way fix.
Garage door opener is very strong and seldom does the chain actually break.
Sometimes the cable will break if it is a combination chain and cable drive system.
The main drive gear is the plastic gear that comes in direct contact with the worm drive gear on the motor.
Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door.
If the chain and cable assembly breaks the door won t move.
In this case the cable can be replaced fixing the problem.
Over time though this slack can increase or the gear and sprocket assembly can wear and the chain may pop off the sprockets.
If your garage door is closing fully and then reversing to open again then it may be due to a problem with the close limit switch.
A garage door opener chain may make a lot of noise when you pull it to open your door but it is one of the most reliable types of door openers ever invented.
Chain drive garage door openers have a sprocket that is attached at the top of the motor.
The chain and cable assembly connects to the trolley and drives the trolley along the rail to raise and lower the door.
For many generations people rely on this type of door opener not only because it is easy to use but also because it is cheap and can easily be repaired when broken.
In order to fix this you ll want to make small changes to the close limit setting until the door opener knows to stop once the door has reached the floor.