Lift cable
A lift cable is the braided steel cable connecting each bottom corner of a garage door to the counterbalance system — winding onto drums in a torsion setup or running through pulleys in an extension setup. The pair carries the door’s full weight in tension every time it moves.
What the cable does, and why its failures cluster
The counterbalance system generates lift at the top of the opening — but the door’s weight hangs from its bottom panel. Lift cables bridge that geometry: anchored to the bottom brackets, they run vertically to the cable drums on the torsion shaft (or through the pulley train in an extension system), converting spring torque into a straight upward pull at the corners. Because the pull comes from the lowest panel, the whole door stays stacked in compression — which is exactly why the bottom bracket, the cable’s anchor, is loaded hardware and carries its own service warnings.
Failures cluster at the ends because that is where the stress does. At the bottom fitting, water and de-icing salt collect, corroding strands right where the cable bends around its anchor. At the drum, the cable flexes through its tightest radius every cycle. Mid-span breaks are rare; whiskered ends are routine. A cable replacement visit runs $150–$260 typically, replaces both sides, and is among the cheapest of the pro-only repairs — the price of the work is low; only the tension it happens under is expensive.
Cable condition, read from the floor
| What you see | What it means | Urgency |
|---|---|---|
| Uniform braid, dull grey | normal service wear | routine — keep the annual look |
| Broken strand whiskers | fatigue at the failure zone | replace soon, scheduled visit |
| Rust bloom at bottom fitting | corrosion in the anchor bend | replace soon — it fails hidden-first |
| Kink or flattened section | a past slack event or pinch | replace; kinks concentrate all future stress |
| Cable off the drum, door crooked | slack event, birdnested shaft | stop using the door; professional call now |
The service rules
Inspection yes, adjustment no
Everything in this entry a homeowner should do happens with eyes and a flashlight. The cables are the loaded delivery lines of the spring system — the same stored energy, one component downstream.
Pairs replace together
Both cables log identical cycles under identical load. New-plus-worn pairing guarantees a second visit and an interim of uneven lift — the two-sided replacement is standard practice, not padding.
Fray is a schedule, not an emergency
Caught at the whisker stage, cable replacement is a calm, cheap line item. Caught at the snap, it is a jammed crooked door at emergency rates. The flashlight minute each season is the arbitrage.
Slack events deserve a cause
A cable that jumped its drum was unloaded by something — floor-strike, obstruction, bind. A visit that re-seats the cable without finding that something has treated the symptom and booked the sequel.
Lift cable questions
The cable came off the drum — what actually happened?
A slack event, almost always. Cables stay seated only under tension; anything that momentarily unloads one side — the door meeting an obstruction, a track bind, hitting the floor too hard on a mis-set travel limit — lets the cable jump its drum groove and birdnest around the shaft. The door then hangs crooked and usually jams. Re-seating requires safely managing spring tension, which puts the fix on the professional side of the line, and the visit should also find the CAUSE of the slack.
How do I inspect my cables without touching anything?
Flashlight, door closed, hands in pockets. Sight along each cable from bottom bracket to drum: healthy cable shows uniform braid and light surface dullness; trouble shows broken strands ("whiskers"), rust bloom at the bottom fitting where water sits, kinks, or flattened sections. The bottom few inches are the classic failure zone — corrosion plus maximum bending. Any whiskers or visible rust pitting is a replace-soon finding worth a scheduled visit at scheduled-visit prices.
One cable snapped but the door still opens — can I keep using it?
Stop. With one cable gone, the surviving cable and its drum carry the full door weight off-axis: the door racks in the tracks, the load doubles on hardware specified for half, and the second failure — cable, roller carriage or track — arrives fast and with more drama. Leave the door in whatever position it holds, disconnect the opener so nobody cycles it by remote, and book the visit. Cable pairs, like spring pairs, replace together.