Cable repair
The cables are what the springs actually pull on. Each side of the door has a lift cable running from the bottom bracket up to a drum on the spring shaft, and the two of them are what keep the door level. When one frays through or jumps its drum, the door tips sideways in the opening, and what was a small part becomes the reason the whole door is jammed.
How do cables fail around here?
- Rust and grit at the bottom bracket. Water off tires and wind-blown dust collect right where the cable wraps, and that is where it frays first.
- A door out of balance. When a spring weakens, the cables work slack on one side and start spooling badly off the drum.
- Something in the way. A shovel handle or a shelf bracket in the cable's path takes it off the drum in one cycle.
Why does a bad cable jam the whole door?
Because the door only stays level while both cables share the load. Lose one side and the panels rack diagonally, rollers bind in the track, and running the opener just drags the door further sideways. Stop cycling it the moment the door hangs crooked; each attempt is more damage than the last.
What does the fix cover?
Set the door level and secure, reset or replace the cables, true up the drums, and then the part that matters: figure out why it failed. A fresh cable on a door that is still out of balance frays again on schedule, so the job should end with the springs checked and the door balanced.
Is this one you can put off?
Not really. A cable fraying strand by strand gives you weeks of warning: rust color at the bottom bracket, a door that sits slightly off-level, a cable riding the edge of the drum. Caught there it is a small job. Caught after it snaps, the door is usually crooked in the track and the bill grew.