What the Cables Do
Your door has two lift cables, one on each side. On most doors they run from a bracket at the bottom corner up to a drum on the spring bar above the door. On doors with springs along the side tracks, they run through pulleys instead. The springs do the lifting, and the cables carry that lift to the door. When one cable frays, slips off its drum or snaps, all the weight shifts to the other side and the door goes up crooked or won't move at all.
Signs of a Cable Problem
- One side of the door is higher than the other, or the door looks twisted in the opening.
- A cable is hanging slack next to the track or lying coiled on the floor.
- Broken wire strands, rust, or a cable that looks like a worn-out shoelace.
- A loud bang, and then the door won't open right. That's often a cable or spring letting go.
If a Cable Breaks
- Stop running the door. With one cable carrying everything, it can jam, come off the track, or drop.
- Keep people and cars out from under it.
- Don't loosen the bottom brackets. They're attached to the cable, and on most doors they're under spring tension even when the door is down.
How Zach Fixes It
He secures the door first, puts on new cables, winds them evenly onto the drums, and adjusts the springs until the door hangs level. Cables usually wear as a pair, so he'll normally recommend doing both sides. He also looks at the drums, the bottom brackets and the springs, because a cable that failed early often has a reason, like a worn spring or a bent bracket. Then he runs the door all the way up and down and checks the auto-reverse.
If the door has come out of its tracks too, see off-track repair. Cables and springs tend to wear out around the same time, so it's worth reading the spring replacement page too.