Quick answer: Telling torsion vs extension springs apart takes one look with the door closed. A torsion spring is a thick coil on a metal bar just above the door opening. Extension springs are long springs running beside the horizontal tracks near the ceiling, one on each side. Both hold dangerous stored energy, so look but never touch, and call if one looks broken.
Key takeaways
- A torsion spring sits on a bar above the door. Extension springs stretch along the tracks, one per side.
- Torsion springs usually last longer and are generally seen as safer, since a broken one tends to stay on its bar.
- DASMA says extension springs need a safety cable running through them. Some older garages still lack them.
- A loud bang, a gap in a coil, a heavy or crooked door, or a frayed cable means stop using the door and call.
How do I tell if my garage door has torsion or extension springs?
You can answer this from the garage floor in about 30 seconds. Close the door, turn on the light and look up. No ladder, and no touching.
Look above the door. A steel bar across the top of the opening with one or two large coils on it means you have torsion springs. The bar ends in round drums on each side, where the lift cables wrap.
Look along the ceiling tracks. Nothing above the door, but a long spring beside each horizontal track, means you have extension springs. They come in pairs, each fastened near the back of its track with a pulley at the front. Look for a thin steel cable running through the middle of each spring. That is the safety cable.
How each spring system lifts the door
The springs do almost all of the lifting. An opener is built to guide a balanced door, not to haul its full weight, which is why a door with a broken spring suddenly feels so heavy.
Torsion springs twist. As the door closes, the cables turn the drums and the spring twists tighter, storing energy. As the door opens, the spring relaxes, turns the bar, and the drums reel the cables back in. Because the work is centered over the opening, the door rises smoothly.
Extension springs stretch. As the door closes, the springs stretch along the tracks like very stiff rubber bands. As it opens, they pull back, and cables running over the pulleys lift the door. Each spring lifts its own side, so a mismatched pair can make the door rise unevenly.
Either way, the energy stays stored while the door is closed.
| What to compare | Torsion springs | Extension springs |
|---|---|---|
| Where it mounts | On a steel bar above the door opening | Beside each horizontal track, one per side |
| How it lifts | Twists, then turns drums that reel in the cables | Stretches, then pulls cables over pulleys |
| Typical cycle life | Usually longer | Usually shorter |
| Safety cable needed | No, the bar usually holds a broken spring in place | Yes, one through each spring (DASMA) |
| Noise | Usually quiet and smooth | Can be louder, with more moving parts |
| What a failure looks like | Loud bang, gap in the coil, door suddenly heavy | Loud bang, loose or sagging spring, door hangs crooked |
Torsion vs extension springs: which is safer and which lasts longer?
In everyday use, torsion is generally seen as the safer design. A broken torsion spring usually stays on its bar. A broken extension spring has to release its energy somewhere, and without a safety cable, the spring and its hardware can whip across the garage.
That is why DASMA’s garage door systems safety tips say extension springs need a safety cable running through the spring, secured to the wall or ceiling.
Neither type is safe to work on yourself. DASMA’s article Torsion Spring Terrorism? notes that torsion spring dangers are “well documented and well known by every garage door manufacturer and garage door dealer in the country,” and it recommends a trained door systems technician.
For lifespan, torsion springs usually outlast extension springs, but the individual spring matters more than the type. Springs are rated in cycles, and one cycle is one trip up and one trip down. DASMA’s technical data sheet on spring cycle life says rough handling, incorrect installation and exposure to the elements all shorten that life, and that “spring cycle life may not necessarily coincide with door cycle life.” In other words, a good door can outlive more than one set of springs.
Why do older Portland and Vancouver garages often have extension springs?
On both sides of the river, ranches and split-levels built before 1990 are more likely to have exposed extension springs. They were a common choice when many of those homes went up, and plenty are still in service. Some never had safety cables, or lost them in a repair years ago. If your garage is in an older part of Gresham, Milwaukie, Hazel Dell or Battle Ground, it is worth a look.
Our weather is a second reason to look. NWS Portland says nearly 90 percent of the year’s rain falls between mid-October and mid-May, and NOAA normals show measurable rain at PDX on about 18 to 19 days a month from November through January. Vancouver’s Pearson Airport runs slightly wetter than PDX in December and January. Garages rarely dry out between storms.
That matters because, as DASMA’s data sheet puts it, “Rust reduces the effective area of spring wire, which in turn reduces its overall strength.” An extension system leaves two long springs, plus pulleys and cables, out in the open. A torsion system keeps its spring in one place, and some designs enclose it inside the bar, so there is less bare steel for damp air to work on. With the fall rains still ahead, now is a good time to catch rust early.
What to look for in a visual check (and what never to touch)
At Larry Myers Garage Doors, we suggest this check once a month, especially before the rains return. Stand on the garage floor with the door closed and look for:
- Gaps in a coil. A torsion spring should be one even, tight coil. A clear gap means it has broken.
- Uneven extension springs. With the door closed, both should be stretched about the same. One that sags or looks longer is a warning sign.
- Missing safety cables. A cable should run through the center of every extension spring.
- Rust. A light film is common here. Flaking or pitted coils are not.
- Lift cables. Frayed strands, heavy rust or slack on one side near the bottom corners all mean call.
- The door itself. A door that hangs crooked, leaves a gap on one side when closed, or jerks as it moves is out of balance.
If nothing looks broken, do the monthly balance test. With the door fully closed, pull the emergency release, lift the door by its handle to about halfway and gently let go. A balanced door stays put. If it drops, rises or feels very heavy, lower it gently and call. Afterward, reconnect the opener as your owner’s manual describes. Our guide to the balance and reversal tests covers both checks.
What never to touch: the springs, the bar and its drums, the extension spring pulleys, the lift cables and the bottom brackets where the cables attach to the door. All of them stay under tension while the door is closed. DASMA says tamper-resistant bottom brackets should be adjusted or loosened only by a trained door systems technician.
When to call a professional
Stop using the door and call if you hear a loud bang, or see a gap in a coil, a heavy or crooked door, a frayed or slack cable, a missing safety cable, or a failed balance test.
Until help arrives, keep people and pets away. Do not run the opener or lift the door by hand. If the door is stuck open, do not pull the emergency release, because without a working spring it can come down hard.
A good spring inspection covers both springs, the cables, the drums or pulleys, the bottom brackets and the safety cables, and whether the springs match the door’s weight. DASMA also recommends a yearly visit from a trained technician.
See our garage door spring repair page, or our garage door repair service if the trouble is cables or rollers. Same-day service is available in Portland and Vancouver, and you can request a free estimate online.
Frequently asked questions
Can extension springs be replaced with a torsion spring system?
Many extension spring doors can be converted to torsion, which usually means quieter operation and no exposed springs along the tracks. It depends on the door’s weight and size, the space above the opening, and the condition of the tracks. A conversion replaces parts under tension, so it is a job for a technician. We can look at your garage and tell you whether it is worth it.
Do all garage doors use two springs?
Extension spring doors always use a pair, one along each track, because each spring lifts its own side. Torsion doors may have one spring or two on the bar, depending on the door’s weight and width. If your door has two springs and one breaks, DASMA recommends replacing both together, since the other spring has done the same work and is usually not far behind.
Why do some doors have a spring above the opening and others on the sides?
They are two ways to store the energy that lifts the door. A spring above the opening is a torsion spring, which twists on a steel bar. Springs on the sides are extension springs, which stretch along the tracks. Which one you have usually comes down to when and how the door was installed.
Can I replace a garage door spring myself?
We do not recommend it. Both torsion and extension springs hold enough stored energy to cause serious injury, and DASMA recommends leaving spring work to a trained door systems technician. The safe part of the job is yours: spot the warning signs, stop using the door, keep everyone clear and call us.
Worried about your garage door springs?
Larry Myers Garage Doors has treated Portland and Vancouver customers like neighbors since 1973: transparent, affordable pricing, same-day service available, no extra charge on Saturdays, work backed by our warranty, and estimates that are always free.
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