How to Replace a Genie Garage Door Carriage Assembly

Close the garage door completely and activate its security lock. Most garage doors use a security lock that slides through a hole in the vertical section of the door roller's C-shaped tracks.

Set up a ladder under the Genie garage door opener. Pull the opener's electrical plug from its electrical receptacle.

Move the ladder to the end of the Genie garage door opener's rail nearest the garage door.

Measure the distance from the closed-limit switch to the end of the garage door opener's rail, using a tape measure. The closed-limit switch mounts to the top of the rail and usually measures about 15 inches from the end of the rail.

Loosen the screw holding the Genie garage door opener's closed-limit switch, using a No. 8 hex screwdriver to turn the screw counterclockwise. Lift the closed-limit switch off the door opener's rail and set the switch aside.

Pry the cotter pin from its hole in the clevis pin, using needle-nose pliers for leverage. The clevis pin holds the garage door's bracket against the carriage assembly. Slide the clevis pin out of its hole in the carriage assembly and lower the garage door's bracket. Set the clevis pin and cotter pin aside.

Pull down on the carriage assembly's release lever, which is the lever with the emergency disconnect cord attached to it.

Push the carriage assembly toward the open end of the Genie garage door opener's rail -- the end of the rail nearest the garage door. Remove the carriage assembly.

Slide the new Genie garage door opener's carriage assembly onto the rail, keeping the release lever facing away from the garage door. The carriage assembly's rounded end, the end that holds the garage door's bracket, faces the garage door.

Slide the carriage assembly toward the Genie garage door opener until it passes the closed-limit switch's mounting location. Slip the limit switch's U-shaped groove over the top of the rail and position the limit switch in its original location on the rail, using the tape measure as a placement guide. Tighten the limit switch's screw, using the No. 8 hex screwdriver to turn the screw clockwise.

Slip the end of the garage door's bracket into the carriage assembly's rounded end. Push the clevis pin through the hole in the carriage assembly's rounded end. Force the cotter pin into the clevis pin's cotter pin hole, using the needle-nose pliers for leverage.

Activate the carriage assembly's release lever, locking the assembly against the Genie garage door opener's rail.