How to Check and Adjust the Chain Drive Tension

Garage Door Chain Tension Adjustment

To achieve proper chain tension, you must release the door from the opener before making any adjustments. When the chain is properly adjusted the chain will be 1/2" (for T-Rail) or 1/4 " (for Square Rail) above the base of the rail at its midpoint.

If the chain is either too loose or too tight, sprocket noise may result.

Below are the steps for adjusting the chain tension, if needed:

1. Run the opener closed using the door button or remote control.

2. 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 T-rail 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.

3. Chain tension is adjusted using two nuts and a threaded shaft located on the inner trolley. If you are inside the garage looking out, you will find these adjustment nuts on the left-hand side of the rail. Loosen the outer nut (the nut closest to the garage door) until the chain droops below the base of the rail, then loosen the inner nut to allow room for the chain to be tightened.

4. 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 T-Rail), 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 1-1/2" high (3.8 cm) object (or 2X4 laid flat) on the floor.
 

*Once you re-engage 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 re-adjust the chain.
 

As of November 15, 2020, Security+ 2.0 Garage Door Openers are now manufactured with obstruction notifications in the event the garage door encounters an obstruction while operating.

For existing Security+ 2.0 Wi-Fi Garage Door Openers that are connected to Wi-Fi, the firmware has been updated automatically so it will now provide obstruction notifications. Note: The garage door opener must be connected to Wi-Fi in order for the update to occur. 

If the opener is not a Wi-Fi enabled Garage Door Opener and is within the warranty time frame, the logic board can be replaced. Replacing the logic board will provide obstruction notifications once it is installed.