Strathroy-Caradoc Garage Door Experts · Strathroy-Caradoc
Chain-Drive Opener Repair: preparing for the visit
Garage Doors · Strathroy-Caradoc, Ontario
The chain hangs in a loop under the rail and slaps against it on every cycle. It used to sit snug. Now the whole house hears the door leave, and the sound has a metallic clatter it never had before.
Worth answering before the call
Can you send a photo of the motor head, the rail and the chain? Is the garage attached and heated, or detached and unheated? Is the noise a rattle along the rail, a clack at one spot, or a grinding from the head?
The door is stuck. Should I pull the red cord?
Yes, if you need the door open and the door is closed or nearly so. Pulling the handle frees the door from the trolley so it can be lifted by hand. Do not pull it while the door is open, because a door with a weak spring can drop. If the door will not lift by hand, or feels very heavy, leave it and mention that when you call, since it points to a spring rather than the drive.
What does the sprocket do, and how does it wear?
The sprocket is the toothed wheel on top of the motor head that pulls the chain. Every cycle drags the chain over its teeth, and over years the teeth wear thin and hooked, letting the chain ride up and skip under load, often at the same point on the rail each time. A sprocket that has loosened on its shaft lags behind the motor. Worn sprockets are replaced as part of the gear and sprocket assembly.