Types of Garage Door Springs: Torsion and Extension
Torsion springs twist above the door; extension springs stretch beside the tracks. Both lift the weight of a North Carolina garage door. A torsion spring rides a steel shaft that holds it when it breaks; an extension spring relies on a safety cable through its coil. Compare how each works, spot which one your door has, see which openers each suits and know when to call a technician.
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What are the different types of garage door springs?
Residential garage doors use two types of springs: torsion springs, which twist on a steel shaft above the door, and extension springs, which stretch alongside the horizontal tracks. Both counterbalance the door’s weight so it lifts by hand or by opener.
The springs, lift cables and drums (or pulleys) make up the counterbalance system. The springs do the lifting; the opener only moves a door that is already balanced. Both types break from wire fatigue, and a snapped spring replacement always covers the pair.
Torsion systems also come enclosed. Wayne Dalton TorqueMaster seals the spring inside the shaft tube, and Clopay EZ-Set is a drive-wound torsion system. Both still twist to store energy, so both count as torsion.
Torsion spring vs extension spring: what is the difference?
A torsion spring stores energy by twisting and turns cable drums on a shaft above the opening; an extension spring stores energy by stretching and pulls cables over pulleys beside each track. The shaft contains a broken torsion spring; extension springs need safety cables.
Torsion and extension springs do the same job, lifting the door’s weight, from different places and with different safety containment.
| Attribute | Torsion spring | Extension spring |
|---|---|---|
| Where it sits | On a steel shaft above the door opening | Beside each horizontal track |
| How it stores energy | Twisting | Stretching |
| Parts it drives | Shaft and two cable drums | Pulleys and lift cables |
| Springs per door | 1 or 2 | 2 (one per side) |
| When it breaks | Stays on the shaft | Held by a safety cable through the coil |
| How it is identified | Wire size, inside diameter, length, wind direction | Color code for door weight per pair, 50–300 lb |
| Wall-mount jackshaft opener | Compatible | Not compatible |
| Who replaces it | Trained door systems technician, in pairs | Trained door systems technician, in pairs |
The row that matters most on a broken door is containment. A snapped torsion spring stays on its shaft. A snapped extension spring stays put only while its safety cable is in place.
How do torsion springs work on a garage door?
A torsion spring works by twisting as the door closes and unwinding as it opens, turning the shaft and the two cable drums that reel in the lift cables. One or two springs per door balance the full door weight.
The spring wraps a steel shaft, typically 1 in across, that runs the width of the door above the header. One end of the spring is fixed to a center bracket bolted to the wall; the other end, the winding cone, grips the shaft. A cable drum sits at each end of the shaft, and a lift cable runs from each drum down to a bottom corner of the door. A 4 in standard-lift drum suits doors up to 8 ft tall.
Closing the door pulls the cables off the drums, which turns the shaft and twists the spring tighter. Opening it lets the spring unwind, turning the drums so they reel the cables back in and lift the door.
A heavier door carries two springs. The right-wound spring sits left of center and the left-wound spring sits right of center, so each one twists the right way. Enclosed systems follow the same count: TorqueMaster uses one spring on a single door and two on a double.
What is an extension spring on a garage door?
An extension spring is a long coil spring running beside each horizontal track that stretches when the door closes and contracts to pull it open. Each spring works through a pulley and a lift cable, with a safety cable threaded through its center.
The fixed end of each spring hangs from the track bracket near the back wall of the garage. The moving end carries a pulley. A lift cable runs from the bottom corner of the door, over a pulley at the front of the track, around the spring’s pulley and back to an anchor. As the door comes down, the cable stretches the spring; as it goes up, the spring contracts and draws the door open.
Extension springs always come in twos, one per side. Each carries a paint color that tells the technician what door weight the pair is rated for: DASMA’s color code runs from 50 lb to 300 lb in 10 lb steps. The safety cable threaded through the coil and anchored at both ends is what keeps a broken spring from whipping across the garage.
Which garage door spring do I need?
The spring a door needs is set by the door’s weight, height and drum, so the existing spring is measured, not guessed. Torsion springs are matched by wire size, inside diameter, length and wind direction; extension springs by the door-weight color code.
Four checks from the floor tell you which type the door has. That is the first thing a technician asks on the phone.
Spring location
Above the header on a shaft means torsion. Along the ceiling beside each track means extension.
Spring count
One or two over the door is torsion. Exactly two, one per side, is extension.
Paint color
A stripe of paint on a torsion cone or an extension spring’s end is a size or weight code the technician reads.
Sealed tube across the header
A closed tube with no visible coil is an enclosed torsion system such as TorqueMaster.
Look, do not touch: the checks work from the floor with the door closed.
Are torsion springs dangerous?
Yes, torsion springs are dangerous to handle because they hold the torque that balances the whole door. The shaft keeps a broken torsion spring from flying loose, but winding, unwinding or removing one releases that energy, which DASMA reserves for trained technicians.
Extension springs carry the same stored energy in a different form. DASMA’s TDS 167 inspection checklist treats an extension spring with no containment cable as a failed item, because a spring that breaks without one has nothing to hold it.
Found a broken spring? Leave the door closed, unplug the opener and keep people and cars clear. The cones, drums, cables and bottom brackets all hold spring tension: leave every one of them to the technician.
Knowing the type tells you what a repair involves, not whether to attempt it.
When to call a technician about a torsion or extension spring
Call when you see a gap in a torsion coil, an extension spring hanging on its safety cable, a slack lift cable, or a door that suddenly feels too heavy to lift and stops a few inches off the floor. Tell us which type the door has and whether it is open or closed.
The technician gives you the price before any work starts, and the work starts only when you say yes. Same-day visits for calls booked by 12 pm, Monday to Saturday. Phones are answered 24 hours a day, 7 days a week. Call (716) 328-9097.
Typical spring repair prices and what moves them are on the cost page.
Next: how long garage door springs last, in cycles and years.