Short answer: Lift cables connect the bottom corners of your door to the springs. When a cable frays, snaps or comes off its drum, the door goes up crooked or not at all. We replace both cables (they wear as a pair), check the drums and bottom brackets, re-tension the springs and balance the door. Same-day service is available across the Bay Area.
What garage door cables actually do
On a torsion system, a steel cable runs from each bottom corner of the door up to a grooved drum on the spring shaft. As the spring unwinds, the drums turn and the cables wind up, lifting the door evenly. On extension-spring doors, the cables run through pulleys along the tracks instead.
The cables carry the full lifting force of the springs. That's why a cable problem is a safety problem, not just an annoyance.
Signs of a cable problem
- The door is crooked: one side higher, or one corner stuck
- A cable is hanging slack beside the door or has come off the drum above
- You can see broken strands or rust where the cable meets the bottom bracket
- The door opens a foot or two, then jams
- You heard a snap but both springs still look intact
Leave the bottom brackets alone. The bracket at each bottom corner, where the cable attaches, is under full spring tension. Loosening those bolts with the springs wound is one of the most common ways people get hurt working on garage doors. If the door is crooked, keep it where it is, unplug the opener and call us.
Why cables fail
Rust at the bottom. The bottom of the cable sits right where rain blows in and where water pools on the slab. In coastal neighborhoods like the Sunset, Pacifica and Alameda, we see cables rusted through at the bottom bracket while the rest looks fine.
Slack from an obstruction. If the door comes down on a trash can or a bike, or a roller catches in the track, the cable can go slack and jump off the drum. When the door moves again, it winds unevenly and binds.
Worn parts rubbing. A bad roller or a bracket mounted too close can rub through a cable over time.
Age. Cables are often original to the door. If your springs have been replaced twice and the cables never were, they're overdue.
How we fix it
- Secure the door so it can't move, then safely release spring tension
- Replace both lift cables with the right length and diameter for your door
- Inspect the drums for cracks or worn grooves, and replace them if needed
- Check the bottom brackets for rust and replace any that are corroded
- Rewind the springs to the correct turns and balance the door
- Check the track for bends and the rollers for wear, since a cable failure often damages both
- Reset the opener limits and test the safety reverse
Cable problems and off-track doors often show up together. Once a cable lets go on one side, the door twists and pulls the rollers out of the track. We handle both on the same visit.
Cables and springs: replace together?
Not always, but often. If your springs are near the end of their life and we're already releasing tension to replace cables, it can make sense to do the springs at the same visit. You save a separate trip. We'll show you how worn they are and leave the decision to you.
Cable repair questions
Can I still use my garage door with a broken cable?
No. With one cable gone, all the lifting force is on the other side, and the door can twist out of its track or fall. Unplug the opener and keep people and cars clear until it's fixed.
Why should both cables be replaced?
They're the same age and carry the same load. If one wore out, the other is usually close. New cables on both sides also stretch and settle evenly, which keeps the door level.
My cable came off the drum but isn't broken. Can you just put it back?
Sometimes, yes, if the cable isn't kinked or frayed and the drum isn't damaged. We'll inspect it and only replace what actually needs replacing.
How do I keep garage door cables from rusting?
Keep the bottom seal in good shape so water doesn't pool at the corners, and have the cables and bottom brackets looked at during a yearly tune-up. In coastal areas, galvanized cables and brackets last noticeably longer.
