The garage door opener loose chain or tight chain can be an easy DIY. Liftmaster and Chamberlain are popular garage door openers with chains. Follow me in this how to fix video on tightening a sagging chain on your garage door opener.
Run the opener closed using the door button or remote control.
Disconnect the garage door from the garage door opener. If you have square rail opener, pull the red manual release rope straight down. If you have a Trail opener, pull the red manual release rope straight down and then back toward the motor unit. This will allow you to open and close the door by hand.
Chain tension is adjusted using two nuts and a threaded shaft located on the inner trolley. If you are inside of the garage looking out, you will find these adjustment nuts on the lefthand side of the rail. Loosen the outer nut (the nut closest to the garage door) until the chain sags below the base of the rail, then loosen the inner nut to allow room for the chain to be tightened.
To add tension to the chain, tighten the outer nut. With every turn of the outer nut, the chain will rise slightly. Keep your eye on the midpoint of the rail. When the chain is approximately 1/2" (for TRail), or 1/4 " (for Square Rail) above the base of the rail, at its midpoint, tighten the inner nut (the nut closest to the motor) to secure the adjustment. The chain is now properly adjusted.
After ANY adjustments are made, the safety reversal system MUST be tested. The door MUST reverse on contact with 11/2" high (3.8 cm) object (or 2X4 laid flat) on the floor.

Once you reengage the door, you may notice some chain droop with the door in the closed position. This is normal. If the chain returns to the correct position when the door is open, do not readjust the chain.




This video was made with Wondershare Filmora.

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