7 Tips for How to Repair a Broken Garage Door Cable

Technically Reviewed by Oleg Chudnovski on Nov 21, 2023 | Written by Fix Appliances CA Editorial Contributors

Garage doors are usually the largest and heaviest on a building, weighing up to 500 pounds or more! Cables attached to tension or torsion springs make lifting and lowering those big doors easier. So, if those cables pop off a pulley, unwind, become detached, or break, moving that door can become a back-breaking exercise. Here are some tips to help you safely repair, replace, reconnect, or rewind garage door cables.

What to Know Before Repairing Garage Door Cables

Before attempting a garage door wire repair, it is important to know what type of cable system it is and how it works. Two common cable systems are used to lighten a garage door for safer operation. One is a torsion spring-controlled cable, and the other is an extension spring-controlled system.

Torsion Spring-Controlled Cables
Torsion springs are commonly mounted horizontally to the header above the garage door opening. It’s a long bar with two high-tension springs coiled around it with a grooved roller drum at each end.

A cable runs from the bottom of each end of the lowest door panel and is secured to the grooved roller. As the door goes up, the cable winds around the roller and loosens the tension on the spring.

When lowered, the cable unwinds, and the tension on the spring winds up. The coil springs are under higher tension when the door is down, making it easier to lift but also putting greater stress on the cables.

Extension Spring-Controlled Cables
Historically, extension springs were reserved for garages with limited headroom for mounting a torsion system. Still, they have become more common in the past two decades as they are easier and safer to install. Instead of mounting the springs above the door and always under tension, they are attached to each horizontal track.

The cables thread a pulley at the end of the spring, go through another pulley where the track bends to go vertical and attach to the bottom-most door panel. The spring is relaxed when the door is up, and the cable is often slightly loose.

As the door lowers, the spring stretches with the cable’s pull and the door’s weight. The spring is fully extended when the door is closed, so it is ready to assist with the door’s weight when it is lifted to open.

Safety Cables
Safety cables thread through the extension springs and are fastened to the door track framework. They don’t impede the spring’s movement but are intended to hold the spring suspended should the door cable break or the spring itself break. Its only purpose is to prevent damage or injury.

Tips On How to Repair a Garage Door Cable

Garage doors are heavy and have multiple moving parts to keep track of and maintain. The cables transfer energy from the coiled springs to lift the door and slow its descent.

A cable can become worn or frayed, disconnected or unbuckled, slip off a pulley, stretch, or break. Knowing how to repair a garage door cable is good when that happens. The type of cable system, whether torsion or extension spring, affects how to reattach garage door cables and how to replace garage door cables.

Inspect the Cable
Regular inspection of the lift cables can help prevent damage or injury. Frayed or rusted cables should be replaced before they break. Cables that sag or appear loose when the door is fully open are more likely to become unwound from drum rollers or slip-off pulleys. The cables may have stretched, or a clamp slipped, causing the sag. Tighten the cables if this occurs.

Clamp the Door
Depending on where the door is, the cable breaks or releases influence this step. If the door is fully or only partially open, attach a C-clamp to the track as near as possible but under the bottom wheel. This will prevent the door from moving downward. If the cable breaks, jumps a pulley or becomes unattached and the door is fully closed, it doesn’t require clamps yet.

Disconnect Garage Door Opener
To prevent damage to the garage door opener, switch off its power source and disconnect it from the door lifting mechanism. This will also allow you to move the door if needed. Locate the release pull rope and give it a tug to unlatch the coupling.

Open the Door
The door must be fully open to release the tension on the torsion or extension springs, making replacing or reattaching cables easier. Lift the door until fully open and clamp it into position to prevent it from rolling down. Heavy doors may require 2 or 3 people to lift, so the door is raised at a level to prevent binding or injury.

Check the Springs
When a cable breaks, it can send a spring-damaging shockwave of energy into an extension or torsion spring. Inspect the springs for cracks or breaks and replace them if damaged. Loose cables may result from slippage by a torsion spring, necessitating tightening and rewinding of the spring.

Be Proactive
If you need to replace one cable due to fraying, rust, or breakage, it’s best to replace both lift cables simultaneously. It’s also a good practice to replace the bottom mounting bracket when replacing the cables. With extension spring doors, check for wear where the cable attaches to the upper frame and replace parts if required.

Use Proper Tools
Use C-clamps or blocks and clamps on both tracks to hold the door in place. Use a ladder or step stool when working above your chest height. It’s safer and provides more strength for tasks than reaching. Use pliers, vice-grips, a hammer, wrenches, screwdrivers, and winding bars as required. Wear safety glasses and gloves for protection, too.

Steps To Fixing a Garage Door Cable

If your garage door cable snapped, came off the pulley, or has become unattached, you have two choices. You can quickly learn how to fix garage door cables or call on professionals. If you choose to repair, here are some steps to follow when fixing a garage door cable safely.

Disconnect Electric Opener
Disconnect the electric door opener from the garage door by pulling the release cord. If the door is partially or fully open, use a C-clamp to prevent the door from rolling closed.

Raise the Door
Lift the door evenly into a fully open position to minimize or release the tension on the extension or torsion springs.

Secure the Door
Use a C-clamp or another method under the bottom wheel guide on each track to hold the door in the fully open position.

Replace Damaged or Broken Cables
Remove the damaged or broken cable(s) from the base of the door and the spring system. Cables commonly loop a pin on the bottom mounting bracket.

• Extension spring cables must be unthreaded from the pulleys and unfastened from the upper frame or rail. Replace cables by looping over the bottom mounting bracket, threading the pulleys, pulling taut, and refastening the frame.
• Torsion spring lift cables must be unwound from the drum and unhooked from the cable slot. Hook the replacement cable in the slot, and wind the cable in the grooves around the drum so the looped end comes out under the drum and loops over the pin on the bottom mounting bracket.

Tighten or Realign Cables
In the raised position, cables are under little or no tension and can be easily realigned on pulleys and tightened. Loosen cables and place them back on pulleys, and then pull the cable taut and retighten the fasteners.

Release Door
Release the C-clamps or blocking mechanisms holding the door open. The door may stay put, roll slightly, or want to roll closed. If it chooses to roll closed, attempt to slow its descent without causing yourself injury. If the springs and cables work, the door should feel much lighter and easier to lift or lower.

Reconnect Electric Opener
Activate the electric opener and allow it to reattach with the lift mechanism. You may need to realign the door opener sensor beams to have the opener work properly.

Test Garage Door Operation
Run the door and opener (if applicable) through several lift and close cycles to ensure the door and cables function properly.

Need Help Repairing a Broken Garage Door Cable?

Repairing a broken garage door cable may be something you don’t feel comfortable doing. If your vehicle is trapped by a heavy garage door that’s jammed or askew, you don’t have the time or tools, or you don’t know how to fix a garage door spring cable, call the pros at Fix Garage Doors CA!
Our service specialists are highly trained, skilled, and experienced in garage door lift cable repair. We install, maintain, and repair overhead, swing-in or out, and sliding garage doors. All our work and parts have a complete warranty; we’re WSIB insured for your protection.

To schedule a garage repair in Newmarket, Aurora, Toronto or the GTA surrounding areas, please text, email, or call our friendly customer support operators. A technician will contact you, discuss the problem, provide an estimate, and book a time and date that works best for you, even the same day! If we provide a repair, the service call is no charge!