Tighten Garage Door Chain
Twist the outer nut clockwise with the wrench to move the trolley and tighten the chain.
Tighten garage door chain. Using your wrench you can start to loosen up the adjusting nut on the side of your carriage closest to the opener head. Slowly turn the outer nut as you watch the slack on the chain above your chalk mark. Chain adjusts by shortening the chain itself. Then use the wrench to tighten this second nut clockwise until the chain is tighter but not so taut that it is completely inflexible.
Turn it counterclockwise holding the other nut in your hand to prevent it from turning. Tightening your garage door chain is a simple matter of turning the right nut. There are only a few ways that the chain can be tightened. A sagging chain is a result of normal usage of the garage door opener.
The one you re looking for is attached to a bolt found at the spot where the trolley or carriage connects to the rail. Watch this video and see the professional at town country door llc demonstrates the. Both adjustment types should be done with the door closed and disconnected from the opener using the emergency release.