Openers · Toronto
Belt-Drive Opener Repair
The belt looks fine from a distance, but up close the rubber has cracked across the back in dozens of places and, in one spot, you can see the steel cords showing through.
In plain words
The most common belt-drive repair is the simplest: the belt has stretched over thousands of cycles and hangs slack under the rail. On its way up it slaps the rail and skips a tooth or two on the sprocket. Tension lives at the trolley, where a threaded shaft, a spring and a square nut set how much the belt is pulled taut. The technician sets that spring to the maker's stated length, confirms a little give at mid-span, then runs the door and listens. If the belt has stretched past what the adjuster allows, or the rubber has aged, a new belt goes in instead.
How the visit goesThe door used to glide up with a soft hum. Now there is a sharp clack every second or so, and if you stand underneath you can see the belt sagging below the rail and slapping it on the way up.
Belt-Drive Opener Repair
How the visit goes
The trolley and its release
The trolley turns the belt's pull into movement of the door and takes every start and stop. The technician checks its two halves: the inner half the belt is fixed to, and the outer half the door arm hangs from. The release lever should part them cleanly when the cord is pulled and lock them together again when the operator runs or the cord is pulled a second time. Cracks in the housing, a lever gummed with old grease, play on the rail, or a trolley sitting hard against a stop bolt are all noted. Whether trolley and motor are in step is checked too, since a belt that has been off the sprocket often leaves them disagreeing.
Gear and sprocket at the motor head
When the shavings on the housing say the drive gear has stripped, the head unit's cover comes off and the gear-and-sprocket kit is replaced as a set. The belt is lifted off the sprocket, the old sprocket shaft and worm gear are withdrawn from the housing, the new gear is greased with the light grease the maker names and fitted with its bushings, and the sprocket is set back on top. The technician checks the motor shaft's end play, since too much play is often why the gear stripped in the first place. The belt is refitted, tensioned and phased, and the operator is run to confirm the sprocket turns true and quiet.
How to check the belt by eye
You leave knowing what a healthy belt looks like from the garage floor. It runs level, just above or inside the rail, with no visible sag between the motor head and the header. Its teeth are even along the whole length and its edges are square, not fuzzy. Every few months, with the door closed, glance up and along the rail; then open the door and look again, since sag shows on the return run. If the belt begins to hang below the rail, slap on the way up or click at the same point each cycle, that is the moment to call, while it is a tension adjustment rather than a stalled door.
Belt-Drive Opener Repair
In the van
Reinforced drive belt with clip
Drive gear and sprocket kit
Rail hanger straps and fasteners
Door arm and clevis pins
Belt tension spring and square nut
Belt-Drive Opener Repair
What affects the quote
Gear and sprocket kit
Shavings on the motor head mean the drive gear is stripping. Replacing the gear-and-sprocket set means opening the head unit, which is more time and a more substantial part than belt work alone.
Sensors and controls needing attention
Photo eyes out of alignment or too high, a wall control below the recommended height or a release handle out of reach are corrected during the visit and listed separately.
Rail straightening or re-hanging
A bent rail, a sagging hanger or a misaligned rail joint that has been fraying the belt is corrected as part of the repair so the new belt runs clean, and the labour appears on the quote.
What to have ready
- Is there a new noise, and where along the rail does it come from?
- Can you send a photograph along the rail showing the belt, and one of the label?
- When did the trouble start, and did it follow a power cut or a pulled red cord?
Belt-Drive Opener Repair: questions
QuestionsWhat information helps when I book a belt-drive repair?
The make and model printed on the motor head, roughly how old the operator is, what the belt is doing and what it sounds like, when it started, whether the red cord has been pulled and whether anyone has adjusted anything. A photograph along the rail showing the belt, and one of the label, settle most questions before the visit.
What are the plastic shavings under the motor head?
They are from the drive gear inside the head unit, which is stripping its teeth. On a belt drive the gear turns the sprocket that moves the belt, so a stripped gear leaves the motor humming and the belt still. The gear-and-sprocket kit is replaced as a set, the shaft's end play is checked, and the belt is refitted and phased.
How often should belt tension be checked?
A look every few months is enough: with the door closed and again with it open, the belt should run level with no sag below the rail. A yearly service that checks tension against the spring length, looks at the sprocket and pulley and runs the balance and reversal tests keeps a belt drive quiet for its whole life. Check again after the first hard cold of the winter.
Related services
- Chain-Drive Opener RepairThe rail shakes when the door runs.
- Garage Door Opener ReplacementDuring the ice storm the power was off for two days.
- Photo-Eye Sensor Alignment or ReplacementSomeone backed the car in a little too far, a bin or a bicycle brushed the track, and since then the door starts to close and comes back up.