How to shorten the length of the rail to make room for a ceiling beam or other obstruction

It is possible to shorten garage door rails, chains, belts, or screws because of space constraints.

Important: The length that you remove from the rail will lessen the distance that the door will open. For example: A standard opener will open a door from 7 to 7-1/2 feet. If you cut 6 inches from the rail, the door will only open 6-1/2 to 7 feet.

Chain Drives

Shorten and Cut the Rail

Cutting a Square Rail

1. Locate the center square rail section and cut the desired number of inches from the female end. It is okay to cut off the tabs. Do not cut the tapered end of the rail section.

Cutting a T-Rail

1. Locate the T-rail section that will connect to the header bracket above the door and cut off the desired number of inches from one end. The idler pulley bracket attaches to the T-rail using two hex screws; therefore, it is necessary to drill two holes in the newly cut end of the T-rail to accommodate this. You can use the piece that has been cut off as a template for drilling these holes.
2. Attach the Idler pulley bracket to the end of the T-rail using the newly drilled holes.

Shorten and Cut the Chain/Cable

Now that the rail has been cut to the correct size the chain/cable must also be cut to fit.

1. Measure the length of the T-rail or Square-rail section that was cut. This is the length that must be removed from both the chain and cable. For example, if 3 inches were cut from the T-rail or Square-rail, 3 inches must be cut from both the chain and cable. This means you must cut 3 inches from the cable and 3 inches from the chain.
2. You will need to re-clamp the cable into a loop (cable clamps are available at most home improvement stores). If you have a complete chain, you would cut the chain double the amount of the rail, 1 foot rail, 2 feet chain. To cut chain, you may need a chain breaker as well as a master link kit which is available at most home improvement stores.

Now that your rail and chain/cable are the correct length you may continue to follow the installation instructions found in your owner's manual. Please note that a shorter rail length may require you to decrease travel limits. Instructions for setting the travel limits are located in the owner's manual.

Belt Drives

Shorten the Rail

Cutting a Square Rail

1. Locate the center square rail section and cut the desired number of inches from the female end. It is okay to cut off the tabs. Do not cut the tapered end of the rail section.
2. Measure the length of the square rail section that was cut off and multiply by 2. This is the length that must be removed from the belt. For example, if 3 inches were cut from the square rail, 6 inches must be cut from the belt.

Cutting a T-Rail

1. Locate the T-rail section that will connect to the header bracket above the door and cut off the desired number of inches from one end. The idler pulley bracket attaches to the T-rail using two hex screws; therefore, it is necessary to drill two holes in the newly cut end of the T-rail to accommodate this. You can use the piece that has been cut off as a template for drilling these holes.
2. Attach the Idler pulley bracket to the end of the T-rail using the newly drilled holes.

Shorten and Cut the Belt

1. Measure the length of the T-rail or Square-Rail section that was cut off and multiply by 2. This is the length that must be removed from the belt. For example, if 3 inches were cut from the T-rail, 6 inches must be cut from the belt.
2. Splice the belt with a new belt clip and link (part # 41B5669). To get instructions on how to install the belt clip see 41B5669, 29B129 and 29B130 Shortening belt kits

Now that your rail and belt are the correct length you may continue to follow the installation instructions found in your owner's manual. Please note that a shorter rail length may require you to decrease travel limits. Instructions for setting the travel limits are located in the owner's manual.

Screw Drives

Shorten the Screw Drive Rail

1. Locate the section of rail that will connect to the header bracket above the door and cut off the desired number of inches from one end.
2. The Rail Brackets attach to the rail using two hex bolts; therefore, it is necessary to drill two holes in the newly cut end of the rail to accommodate this. You can use the piece that has been cut off as a template for drilling these holes.
3. Attach the Rail Brackets to the end of the rail using the newly drilled holes.

Now that your rail is the correct length you may continue to follow the installation instructions found in your owner's manual. Please note that a shorter rail length may require you to decrease travel limits. Instructions for setting the travel limits are located in the owner's manual.