Just about everyone is familiar with the garage door opener, the extension or torsion springs, the remote that sends the “open” or “close” signal to the door and the panels of the garage door itself. Many people today are even able to control their garage door from halfway around the world by way of an app on their smartphone. But while homeowners tend to be better informed than ever about their garage doors there’s still one component of the entire mechanism that can leave them scratching their heads: the cables. There are actually several different cables at work on most contemporary garage doors and below we’re going to take a look at them and what they do.
The Different Cables and Their Jobs
You may hear someone complain that their garage door cable broke. Or, if you have been having a problem with your door, the repairman might tell you that you have a broken cable that needs replacing. But what kind of cables are used on garage doors and what is their job? Let’s take a look.
- The lifting cable - This is the cable that is most likely to break on a garage door. This is a heavy duty wound steel cable that is attached to the bottom corner of the door and then up to a drum attached to an axle. That axle runs through a torsion spring that provides the power needed to open the door. So, the torsion spring unwinds, which turns an axle, the axle turns the drum and the drum spools and unspools the cable which lifts and lowers the door. If this cable snaps the opener is going to struggle trying to lift the door itself.
- The retaining cable - Old or overstressed torsion and extension springs are prone to snapping. This by itself is an extremely dangerous event and you should hope you are never anywhere near a spring when it snaps. However, a snapped spring would be even more dangerous if it were allowed to simply crash to the floor of the garage in large, jagged pieces. These could do serious damage to your car and prove fatal if they were to strike someone on the head. The retaining cable runs through the extension or torsion spring. Its only purpose is to wait for that day when the spring snaps and to prevent the broken pieces from falling and hurting someone or damaging your car or other items in the garage.
- The emergency release cable - Most folks aren’t aware that their automatic garage door comes with an emergency release cable. But it does. In the event that the power goes out and the opener motor is unusable pulling the emergency release cable will disconnect the door from the motor and allow you to open it manually. You’ll find the emergency release cable just inside the garage, hanging from above at the center line of the door.
If a technician says your garage door cable snapped, they’re most likely talking about the lifting cable. Not the emergency release cable or the retaining cable.
Why Do Lifting Cables Snap?
The lifting cable is engaged every single time the door is opened and closed. Most wind up coiling onto and off of a drum attached to an axle projecting out from the torsion spring. All the friction from moving up and down, winding and unwinding, while holding aloft hundreds of pounds causes the cable to fray. The steel cable is also exposed to the cold, heat and moisture of the outdoor environment. And this causes corrosion that further weakens the cable over time.
In addition, if the door is even a tiny bit out of alignment this can bring enormous stresses to bear on the cable and can cause it to rub on parts of the door mechanism it should not be in contact with. This only accelerates the process of wear and tear. The sum total of all this stress, corrosion and wear and tear is a broken cable.
How Do I Know If the Cable Has Snapped?
There are a couple of things you can look for that will indicate that the lifting cable has snapped and needs to be replaced. These include:
- The door is struggling to open - Sometimes the motor will appear to be working fine and the spring or springs also seem to be intact. Yet for some unknown reason the door is struggling to open. If this happens to your door it’s likely either a broken spring or a broken lifting cable and it will need to be repaired ASAP.
- You see what looks like a wire hanging loose - If you notice what looks like a wire hanging loose beside the door it’s likely the remains of the lifting cable that has snapped. These cables can become extremely frayed prior to breaking and the process of snapping frays the individual strands even further.
How to Prevent the Lifting Cable from Breaking
The best way to fend off the untimely and potentially dangerous snapping of the lifting cable is to schedule regular maintenance of your garage door. If the technician notices excessive wear and tear of the cable during one of these visits they can easily replace it with a new one. Even so, you should take a few minutes every month and visually inspect the cables just to make sure they’re not frayed or rubbing up against anything as they move.