Cables transfer the spring’s lifting power to the door. When one frays or snaps, the door goes crooked fast — and forcing it makes everything worse.
Garage door cables are braided steel lines that run from the bottom corners of the door up to the drums on the torsion shaft (or along the extension springs on older systems). Every ounce of the door’s weight moves through them on every cycle, so they live under constant tension and eventually wear out.
The tell-tale failure: the door suddenly sits crooked in the opening, slams down on one side, jams halfway, or you spot a cable hanging slack or coiled on the floor. Stop using the door at that point — one cable is now carrying a two-cable load.
Cable failures rarely come out of nowhere. The common causes:
The cables themselves are inexpensive parts — which tempts DIYers every day. The catch: replacing them requires releasing and re-applying torsion spring tension, and the bottom brackets they anchor to are under the same lethal tension as the springs. This is functionally spring work with extra steps, and it belongs to someone with winding bars and the scars of experience.
Professional cable replacement is a routine, single-visit job, and pros replace cables in pairs for the same reason they replace springs in pairs: matched wear. A good tech will also inspect drums, bottom brackets, and spring condition while everything is de-tensioned — the marginal cost of fixing it all in one visit is small.
Expect roughly 45–90 minutes: secure the door and de-tension the springs, remove the damaged cables, inspect and replace worn drums or brackets if needed, install matched new cables, re-tension and rebalance, then cycle-test with the opener force limits re-checked. You should get a door that tracks evenly with no slack visible on either side at any point of travel.
No. The remaining cable and the spring system are now loaded asymmetrically — doors in this state jump tracks, bend panels, and occasionally drop. Disconnect the opener and leave the door closed until it’s repaired.
Typically 8–15 years or roughly in step with a spring cycle-life. Coastal humidity and salt shorten that considerably — annual inspection catches fraying before it strands you.
Often yes — a jumped cable can sometimes be rewound and re-seated after finding the cause (usually an obstruction strike or slack event). It still requires de-tensioning the system, so it’s the same class of service call, just lighter on parts.