Garage Door Torsion Springs 101

Have you ever wondered why your garage door is so easy to open, even though it’s such a huge piece? Torsion springs are a simple but genius part of any garage door that serve to stabilize the door, do most of the heavy lifting when opening it, and prevent it from falling shut once you have got it up. For most homeowners, however, the importance of a torsion spring only becomes evident when one needs repair or replacement.

A garage door will have either one or two torsion springs on the long metal shaft above when viewing from the inside. Using a device called a winding cone on the end of the spring, significant torque is shifted from the spring to the shaft. This torque is ultimately transferred to the cable drums located on the ends of the shaft. The cables wound around the cable drums are attached to the door and are what ultimately lifts the garage door, using the power of the torsion spring.

Torsion Spring Installation

When torsion springs are installed, the spring is wound (using the winding cone) to the point where there is just barely not enough torque to lift the garage door. This way, the door stays shut even when not locked, but it is still easy for you or your opener to lift the garage door when you need to…you only need to add a small amount of power to make up the difference.

As the door moves up, the torque left in the spring goes down, so the amount of power they lend toward lifting the door also goes down. In theory, this means you would have to put more strength behind lifting the higher the door goes. This effect is minimized using rollers, attached to the garage door and seated in tracks. At first, the tracks are vertical, so all the weight is supported by the torsion springs (via the cables wound around the cable drum) and you (or your automatic opener). As the door lifts, these rollers move to the horizontal track, so the tracks themselves are now supporting part of the door and reduce the power needed to continue lifting it.

Once the door is totally lifted, the rollers on the very bottom of the door will normally not be on the horizontal part of the track, so the door will want to fall. But at this point the torsion springs are wound so they have just enough power to keep the door open. This means the door remains stable when open, but is still easy for you or your opener to slide so you can close the door at any time.

Repair or Replace Spring?

It is usually easy to tell if you need to repair or replace your torsion spring: it will completely snap in half and cease functioning! Installation of a new torsion spring can be tricky and very dangerous if you do not use the proper tools and procedures, so employ a professional garage door service and repair company like Mile High Garage if you are inexperienced or would just rather a professional handle the job for you.

If your garage door simply does not feel right – it takes too much strength to open, or does not remain open after you lift it fully – it may be because a torsion spring is not wound properly. The winding cone on the spring will let you adjust the exact amount of force it exerts on your door to “tune” it properly. This repair is less dangerous than replacing a spring, but if a spring comes loose during the process and you are not using the proper tools or methods, you can still seriously injure yourself. Be careful!