If you find your garage door not opening or closing properly, or it makes a noise, the chain may need adjusting. Chain drive garage doors employ a chain connected to a motor to raise and lower doors. The chains can eventually loosen from constant opening and closing. You should be able to adjust the chain opener tension yourself by following these tips.

Prepare to Adjust the Chain Opener

To fix the garage door chain opener, gather:

  • tape measure
  • chalk
  • step-ladder
  • adjustable wrench
  • two open-end spanners

To make certain you have a problem with the chain, test the door for squeaking or slapping by raising and lowering .it several times. Ensure no one walks under the door while you work, and test safety reverse sensors after each adjustment.

Slapping, groaning, or squeaking commonly indicates chain problems. If the chain has broken, you will need to replace it, or call a professional to replace it. Otherwise, proceed to adjust the chain after you determine it is loose. 

Measure the distance between the garage door motor and the opener rails. Divide this number by two for the middle point, and mark it. An adjusted chain should come one-fourth inches on top of the mark and one-half inch for T-style rails. 

Detach the Door From the Opener

Plan another path out of the garage before you lower it. Lower the door, then set a step-ladder to reach the power supply, and detach the wires, or shut off power from the breaker box. If you disconnect wires, take a photo of them to remember how they connect.

Locate the trolley, the metal rod threaded that moves the rail, and pull the release cord to detach the opener from the door. On T-rail models, pull the cord down, then toward the motor.

Adjust the Tension

Locate the threaded shaft, the part that threads through the metal trolley flange. The shaft commonly has bolts with two nuts on the left side of the rail.

To tighten the chain, find the inner nut on the trolley shaft the closest to the chain with a washer against the flange. Hold the outer nut with your hand, and use the wrench to turn it counterclockwise, and avoid making it too tight, so it won't wear out the rollers. 

Rotate the outer nut clockwise until it reaches the mark, then rotate the inner nut again to secure. Proceed to rotate the outer nut until the nut and washer fit snug against the flange. To relieve tension, loosen the outer nut it gets under the rail base, then slightly loosen the inner nut.

For more information, contact a business like J & B Door.