Extension or torsion springs? How to tell, from the garage floor

Two different machines get called “garage door springs,” and they sit in two different parts of the garage. Once you know where to look you can tell yours apart from the floor, door closed, nothing in your hands. Worth doing before you call anyone, because the type changes what the repair is and what the risk is, and it decides whether you have a decision to make at all.

Go in through the house door, leave the opener alone, and look at the wall above the opening first. Then at the side walls above the horizontal tracks.

Where are the springs, above the door or along the side walls?

If there is a metal shaft running across the wall above the door with one or two thick coiled springs threaded onto it, you have torsion springs. If that wall is bare and you instead see two long skinny springs stretched front-to-back above the horizontal tracks, one down each side wall, you have extension springs. Doors have one system or the other. Never both.

That is the whole identification. Everything below is detail for whichever one you found.

What do extension springs look like up close?

Extension springs work by stretching. Each one runs parallel to the horizontal track a little above it, anchored at the back end to the track hanger and attached at the front to a pulley. The lift cable wraps that pulley and runs down the side of the door to the bottom bracket. It is all out in the open, and all of it doubled, one set per side wall.

The giveaway is movement. Raise the door and watch. Extension springs visibly shorten and go slack as the door comes up, then stretch out long and tight when the door is down. Coils that touch each other at rest and spread apart under load, that is extension.

They are also the springs people hang things on. In a detached single-car garage the spring sits at about the height where rakes and ladders go along the side wall, so that is where they end up. Take anything off that is hanging there and leave the spring alone.

What does a torsion setup look like?

Torsion springs work by twisting. One or two springs sit on a steel shaft mounted to the header above the door, usually bolted through a stationary center bracket, with a cable drum at each end of the shaft. The cables come off those drums and drop straight down to the bottom corners of the door.

Watch this one move and the springs stay the same length. The shaft rotates and the coils wind tighter or unwind.

A broken torsion spring is easy to read from the doorway. The coil that was one continuous spiral yesterday now has two ends somewhere in the middle of it, sprung apart.

Why do so many older Howard County garages still have extension springs?

Two reasons, and both are about the building rather than the door.

Headroom is the first. A standard torsion setup needs a clear band of wall between the top of the open door and the ceiling, enough to carry the shaft, the springs on it, and the brackets holding the whole assembly. A lot of the older ranches around Kokomo, and the farmhouse garages out toward Sharpsville and Greentown, were framed with rafters or a low header sitting right on top of the opening. There is no band of wall to put a shaft on.

Cost is the second. Extension was the cheaper package for a builder hanging a single wood door, and on a narrow door it worked well enough that nobody went back and changed it. So the springs you are looking at may be the third or fourth set installed on the original layout.

None of that makes extension springs bad. A matched pair, sized to the door and fitted with safety cables, runs a single door for years.

What does the safety cable through the spring do?

A safety cable is a thin steel cable threaded through the hollow center of each extension spring and bolted down at both ends, to the track hanger at the back and to the front hardware. It does nothing at all until the spring breaks. At that instant a spring stretched tight across your garage has a lot of stored energy and two loose ends, and the cable is what keeps both halves strung on a line instead of whipping across the bay.

Check yours right now. Follow each spring end to end and look for a second, much thinner cable coming out of the coil and anchored at the hardware. If the springs are hollow and empty, they are uncabled, and that is worth fixing on its own visit even while the springs are still good. Uncabled extension springs are how a broken spring ends up through drywall or across the hood of the car parked underneath.

Don’t confuse safety cables with lift cables. The lift cables are the ones carrying the door’s weight down to the bottom brackets. They wear through in stages you can see, and checking them takes about a minute.

When is converting to torsion worth it?

Conversion is a real upgrade on the right door and wasted money on the wrong one. The cases where it pays:

• You are replacing the door anyway. New door, new hardware, and the labor is already on site. By far the best moment to do it.
• One side of the door sags or leads going up. Two extension springs pulling at slightly different rates rack the door. A single torsion shaft pulls both sides through the same rotation.
• Second extension failure in a few years. If the pair keeps breaking, the springs are undersized for what the door actually weighs, and re-sizing on a torsion shaft is the more precise fix.
• A wide two-car door. Heavy and long, and torsion carries that span more evenly and more quietly.

Both systems get quoted, so you can compare what each one runs in Howard County before you decide.

Which doors should stay on extension springs?

A single-car door with no clear wall above the opening is the plainest keep. Low-headroom torsion kits exist, but they need different brackets and a shortened shaft arrangement, and you would be paying for hardware to solve a problem the extension setup already solved. Same answer if the springs are due for replacement and the door tracks straight: replace the pair, add the safety cables if they are missing, and put the money into the door itself.

Three things to look at, one to measure

A minute with a flashlight, door closed, and whoever answers the phone can quote you properly instead of guessing:

1. Above the door or along the tracks. That tells us torsion or extension.
2. How many springs. One or two.
3. Whether a thin cable runs through the middle of each extension spring.
4. The gap between the top of the opening and the ceiling, measured with a tape. That number decides whether a conversion is even on the table.

Bring those to the call and our spring and cable page covers the rest, including what happens on the visit. If you already heard the bang and the door is sitting crooked, skip the tape measure and call.