A cable on my garage door is hanging loose

Likely causes, most common first

A cable that slipped off its drum is the usual reason, ahead of a broken spring that let both cables go slack.

1. Most common

   The cable slipped off its drum

   The sign: The cable is whole but hangs in a loop near the bottom corner or sits bunched beside the drum, often right after the door came down on a bin, a bike or a lip of ice.

   The fix: Secure the door, take the tension off the springs, rewind the cable into the drum grooves, and correct whatever made it go slack. Garage Door Cable and Drum Repair, from $189

2. Common

   A spring broke and the cables lost tension

   The sign: Both cables look loose, the door is heavy or will not move, and one torsion spring shows a clear break in its coil.

   The fix: Fit a new spring, or two on a door built with a pair, then reset both cables and balance the door. Garage Door Spring Replacement, from $249

3. Common

   The cable frayed or snapped

   The sign: Broken strands bristle near the bottom bracket, the cable ends in a frayed tail, and that corner of the door has dropped below the other.

   The fix: Replace both lift cables as a pair, since the other one carries the same wear, and check the drums for cracks or worn grooves. Garage Door Cable and Drum Repair, from $189

4. Less common

   A bottom bracket rusted or pulled loose

   The sign: The cable is intact, but the bracket it hooks into at the bottom corner is rusted through, bent, or tearing away from the bottom section.

   The fix: Replace the bracket, and any rotted edge of the bottom section, with the springs fully unwound, then reattach and tension the cable. Garage Door Cable and Drum Repair, from $189

5. Less common

   The door came out of its track

   The sign: Rollers sit outside the track on the slack side, the door is twisted or wedged, and a section may be bowed.

   The fix: Clamp the door in place, guide the rollers into realigned or new track, and fit new cables if the old ones kinked. Off-Track Garage Door Repair, from $179

What you can safely check in two minutes

Look, photograph and stay back: every check below is done with your hands at your sides.

• Note which bottom corner the loose cable hangs from and whether that end of the door rests lower.
• Look up at the drum on each end of the torsion shaft to see whether cable is still wound in the grooves or has unspooled.
• Check the springs above the door for a break in a coil; on an older door, check that neither side spring along the ceiling has come apart.
• See whether any roller has left its track or a section looks bowed or twisted.
• Take photos of each lower corner, each drum and the springs from a step back so the parts can be confirmed by text.

Why a slack cable is a tension problem

The lift cables are how the springs hold the door up, so a slack cable means that corner has lost its support while the springs may still be wound.

On a torsion door, each cable runs from a bracket at a bottom corner up to a drum on the torsion shaft. The springs turn the shaft, the drums wind the cables, and the door rises as if it weighed very little. Take one cable out of that loop and the weight lands unevenly.

That is why a loose cable means stop. The bracket at the bottom can still be under load, the door can tilt or drop on the slack side, and the opener can wedge it crooked in the tracks. Extension-spring doors run their cables over pulleys instead, with the same risk.

Rust at the bottom corners in a wet climate

Cables and bottom brackets tend to fail at the lowest point of the door first, where rain and driveway splash keep the steel wet.

Portland's airport averages about 157 days a year with measurable rain, and Vancouver's Pearson Field logs roughly 163. The lower end of each cable and the bracket it hooks into sit in that damp zone at the slab, and rust there weakens strands well before a cable looks badly frayed.

In Vancouver's Hough neighborhood and the similar prewar grids nearby, where some garages still hang aging wood doors, we check the brackets and the lower edge of the bottom section on every cable job. Galvanized cables and a sound bottom seal both help the next set last.

When a loose cable becomes urgent

A loose cable already calls for a repair, and any of these moves it to the top of the list.

• The door stopped partway or stayed open, with the slack side hanging lower.
• The cable that still looks attached has broken strands of its own.
• A bottom bracket is bent, rusted through or tearing out of the door.
• Rollers have left the track or the door is wedged at an angle.
• Someone has already tried to loop the cable back onto the drum.

How a cable repair goes

A loose cable is usually fixed with a new pair of lift cables, a drum and bracket inspection, and a full rebalance.

1. Clamp the door and unwind the springs

   We clamp the door to the track and take the tension off the springs with winding bars.

2. Replace both cables

   Both cables come off even if only one failed, and drums with chipped grooves or brackets with rust scale get replaced while everything is slack.

3. Level the door and retension

   The new cables are wound to matching lengths so the door hangs level, then the springs get their turns back.

4. Watch a full cycle

   We run the door open and closed and watch both cables pay out cleanly from the drums.

Related pages

Repairs, symptoms and guides that connect to this page.