Springs do the heavy lifting
A garage door can weigh well over a hundred pounds, and much more for large, insulated or wood doors. The opener doesn't lift that weight on its own. The springs do. They're wound or stretched to counterbalance the door, so that a properly adjusted door feels light when you lift it by hand and stays put when you let go halfway up. When a spring breaks, the opener suddenly has to lift the full weight of the door, and it often can't.
Signs of a broken or worn spring
- A loud bang from the garage, often while the door is closed and nobody is using it. That's frequently a torsion spring snapping.
- A visible gap in the coils of the spring above the door.
- The door won't open, or opens a few inches and stops, while the opener motor runs.
- The door feels very heavy when you try to lift it by hand with the opener disconnected.
- The door slams shut or won't stay in place when partly open.
- Cables hanging loose or off their drums at the sides of the door.
- The door rises unevenly, with one side higher than the other.
Torsion versus extension springs
- Torsion springs mount on a bar above the door and twist to store energy. They're the most common type on modern doors and generally give smoother, more balanced operation.
- Extension springs run along the horizontal tracks on each side and stretch when the door closes. They should always have safety cables running through them so a broken spring can't whip across the garage.
If your door has extension springs without safety cables, ask a technician to add them or to discuss converting to torsion springs.
Why this isn't a do-it-yourself job
Garage door springs store a great deal of energy. Winding or unwinding a torsion spring with the wrong tools, or removing a spring under tension, can cause serious injuries. The same goes for the cables, drums and bottom brackets, which are under tension from the springs. This is one repair best left to someone with the right tools and training.
What you can do safely is stop using the opener when you suspect a broken spring, keep people and cars clear of the door, and leave the door where it is until the technician arrives.
What a proper spring replacement includes
1. Identifying the correct spring size for your door's weight, height and drum size, rather than guessing. 2. Replacing both springs on doors with two, since the second spring is usually close to failing too. 3. Inspecting and, if needed, replacing cables, drums, center bearing and end bearings. 4. Adjusting the springs so the door is balanced: it should stay roughly in place when lifted halfway by hand. 5. Lubricating springs, hinges, rollers and bearings. 6. Testing the opener's force settings and safety reversal after the door is balanced.
High-cycle springs
Springs are rated by how many open-and-close cycles they're expected to last. If you use the garage door as your main entrance and open it many times a day, ask about higher-cycle springs. They cost more but can last considerably longer.
Questions to ask
- Which springs are you installing, and how were they sized for my door?
- Will you replace both springs, and why or why not?
- Are cables, drums or bearings worn, and what would replacing them cost?
- What warranty comes with the springs and the labor?
- Will you test the opener's safety reversal when you're done?