Garage door cable frayed or rusty?

Lift cables are stranded steel, and the strands break first at the spot where the cable bends or is gripped. Broken wire strands, called "birdcaging" or "fishhooking" when they stick out, are the signal that the cable is losing capacity. The cable is not going to fail on the day you first see them, but each broken strand moves the load onto its neighbors.

Rust matters most at the bottom end, down near the bottom bracket, and where the cable passes over the drum. Surface rust on an otherwise tight cable can be cosmetic. Rust that has pitted the wire, or a cable that has stiffened and stopped bending smoothly, is a different thing. Road salt, wet garage floors, a leaking roof, and condensation on cold mornings all speed this up in our area.

People often ask whether they can just tighten a slack cable. Please do not. The cable ties directly into the torsion spring tension and the bottom bracket, which are under very high load. Adjusting one side changes how the door is balanced and can lock in a lean. An accident with a loaded cable or a released bracket can cause serious injury. Slack is also a symptom, not the cause. It usually means the cable has slipped off the drum or the spring has lost its balance.

A frayed or rusty cable is a repair, and a good time to do it, because replacing it before it breaks avoids a dropped door and a larger repair. We normally replace both cables together.

If the cable has already rubbed through a section or the bracket is torn, a section replacement might be needed as well. We will point it out before anything is done.