garage door cable

What is a Garage Door Cable?

A garage door cable is a high-strength steel cable that works with the springs, pulleys, and other hardware to lift and lower the door smoothly and safely. They are under extreme tension and are a vital safety component. There are two main types, corresponding to the two main types of garage door springs.

1. Types of Garage Door Cables

A. Torsion Spring Cables (Horizontal Springs)

• Location: The spring is mounted horizontally on a metal shaft above the closed garage door.

• Function: These cables are attached to the bottom corner of the door on each side. They run up and through a drum that is attached to the torsion spring shaft.

• How it Works: When the spring unwinds, it rotates the drum, which winds the cable around it, lifting the door. Lowering the door winds the spring back up, storing energy for the next lift.

B. Extension Spring Cables (Vertical Springs)

• Location: The springs are mounted vertically on either side of the door track.

• Function: These are primarily safety cables that run through the middle of the extension spring.

• How it Works: The main lifting force comes from the springs themselves stretching and contracting. The safety cable's sole job is to prevent a catastrophic accident. If the extension spring breaks, the cable will contain the metal pieces, preventing them from flying across the garage like a dangerous projectile.

2. Key Components and Terminology

• Lifting Cable: The main cable that does the work of lifting the door (used in torsion systems).

• Safety Cable: The cable that runs through an extension spring for containment.

• Bottom Bracket: The heavy-duty bracket at the bottom corner of the door where the lifting cable is attached.

• Drum: The pulley-like component on the torsion spring shaft that the cable wraps around.

• Cable Plate: A securing plate on the drum where the end of the cable is anchored.

3. Importance and Warning Signs

Garage door cables are under immense tension. A broken or frayed cable can cause the door to fall suddenly or operate unsafely.

Signs of a Problem:

• Visible Fraying: Any sign of broken strands or wear on the cable is a major red flag.

• Door is Uneven/Crooked: If one cable is loose or damaged, one side of the door may hang lower than the other.

• Loud Popping or Snapping Sound: This often indicates a cable or spring has broken.

• Door Won't Open or is Very Heavy: A malfunction in the cable system prevents the springs from doing their job, putting all the strain on the opener.

• Cable is Off the Drum: If the cable has jumped off its track on the drum, the system will not function correctly.