When a garage door cable came off its drum, the door loses its lift on that side. The opposite cable keeps pulling, so the door twists in the opening and jams. It looks dramatic, and it is one of the repairs where a wrong move makes things worse quickly.
What the cables do
A sectional garage door has two lift cables, one on each side. Each cable is fixed to a bracket at the bottom corner of the door and winds onto a grooved drum at the end of the spring shaft. The springs turn the shaft, the drums wind up the cables, and the cables raise the door. Springs supply the force. Cables deliver it.
Why a cable comes off or breaks
Rust at the bottom bracket
This is the big one around Attleboro. Cars carry road salt and slush into the garage all winter. It drips off, pools along the threshold and sits against the bottom brackets and the lowest few inches of cable. Galvanized cable resists rust for years, then individual strands start to break. Once a few strands go, the rest follow.
The door closed on something
If the door comes down on a bin, a bumper or a shovel, one side stops while the other keeps moving. The cable on the stopped side goes slack for a moment and can jump out of its groove on the drum.
A broken spring
When a spring snaps, the shaft loses tension and both cables go loose. They often unwind and drop off the drums. In that case the cables are a symptom. See what to do when a garage door spring breaks.
Worn drums, bearings or pulleys
A cracked drum, a seized end bearing or a worn pulley on an extension spring door makes the cable track badly and fray against metal edges.
Warning signs before a cable fails
- Loose strands sticking out from the cable like wire bristles.
- Rust stains or a brown crust on the cable near the floor.
- The door rising unevenly, with one corner leading.
- A gap under one side of the door when it is closed.
- A cable that looks slack when the door is fully open.
Catching these early turns an emergency into a planned visit. They are part of our garage door maintenance checklist.
What not to do
Do not run the opener to try to level the door. It will pull the door further out of square and can bend the tracks or crease a panel. Do not try to rewind the cable onto the drum by hand. The spring is still loaded, and the bottom bracket holding the cable is under the full tension of that spring. Never loosen a bottom bracket on a door with wound springs.
Keep people away from the door, do not park under it if it is partly open, and unplug the opener.
How cable repair is done
For a proper garage door cable repair, the door is secured first and the spring tension is released under control. Both cables are replaced, since they wear together. The drums and bottom brackets are inspected, and rusted brackets are changed along with the cables. Each cable is then wound evenly onto its drum, the springs are tensioned, and the door is checked for level and balance by hand.
If the door jammed hard, the rollers and tracks are checked as well. A roller that popped out during the jam needs roller and track repair before the door is safe to run.
Help with a garage door cable in Attleboro
Johnny Garage Door Service has 30 years in business and handles cable, spring and track problems across Attleboro and the nearby Massachusetts towns. Call (508) 709-6644 and describe which side is hanging and whether the door is open or closed. For other problems, start with our page on Attleboro garage door repair.