Torsion vs Extension Springs: What Is On Your Door?
Torsion springs sit on a steel shaft above the door opening and wind up as the door comes down. Extension springs stretch along the horizontal tracks on either side of the door. Torsion is the standard on modern doors because it balances the weight more evenly, lasts longer and stays put when it breaks. Every extension spring needs a safety cable threaded through it.
Walk into your garage and look up. What you find above the door or along the ceiling tracks tells you which of two counterbalance systems is holding the weight, and that changes what a repair costs, how the door behaves and what safety hardware needs to be there.
How do you tell which one you have?
Stand inside with the door closed and look directly above the opening.
Torsion. A steel shaft runs horizontally across the header, roughly a foot above the door. One or two springs are mounted on that shaft, held by a center bearing plate in the middle and cable drums at each end. The springs are tightly coiled and look like fat steel sausages.
Extension. Nothing above the opening. Instead, two long thin springs run parallel to the horizontal tracks that carry the door back into the garage, one on each side, anchored to the rear track hanger and hooked to a pulley. They visibly stretch as the door comes down.
Older Richardson ranch homes from the 1960s and 1970s often still run extension springs on single width doors. Newer builds in Frisco and north McKinney almost always run torsion.
How does each one actually work?
Both store the door’s weight as energy and give it back on the way up. They get there differently.
A torsion spring twists. As the door closes, cables wind onto drums at each end of the shaft and the springs wind tighter. When you lift, the springs unwind and turn the shaft, the drums pay the cables back out and the door rises. The load pulls straight down through the center of the opening, which keeps both sides even.
An extension spring stretches. Each spring pulls against a cable and pulley system on its own side of the door. Because each side is independent, the two springs have to be matched and adjusted in step. When one weakens faster than the other, the door starts to rack and bind in the track.
Why do extension springs need safety cables?
This is the part worth reading twice.
A torsion spring that breaks stays where it is. It is threaded onto a shaft and captured at both ends, so it splits and stops.
An extension spring that breaks is a loose length of stretched steel under tension with a hook on each end. With nothing running through it, it can whip across the garage. The fix is a safety cable, a steel cable threaded through the middle of the spring and anchored at both ends, so a break leaves the pieces strung on the cable like beads.
Safety cables are inexpensive and standard practice. Any extension spring setup without them should get them, and we add them as a matter of course on any spring replacement involving extension springs. If you have extension springs in Richardson or east Plano and you cannot see a cable running down the middle of each spring, that is worth a call on its own.
Which one is better on a modern door?
Torsion, for most homes, for reasons that have nothing to do with price.
| Torsion | Extension | |
|---|---|---|
| Where it sits | Shaft above the opening | Along both horizontal tracks |
| Headroom needed | About 12 inches | Works in low headroom |
| Balance | Even across the door | Depends on both sides matching |
| Typical cycle life | 10,000 standard, 25,000 high cycle | Commonly shorter |
| On failure | Stays on the shaft | Can whip without a safety cable |
| Door travel | Smoother and quieter | More bounce and side to side movement |
| Suits | Doubles, insulated doors, heavy doors | Light single doors, tight headroom |
| Typical installed cost | $220 to $400 single, $340 to $620 pair | $170 to $330 per pair with safety cables |
Typical installed ranges for Collin County, reviewed September 2026.
The even pull is the real argument. A torsion setup lifts through the middle of the shaft, so the door rises square, the rollers stay seated and the opener works against a balanced load. That shows up as less wear on the track, the rollers, the hinges and the opener gear.
Extension springs still have a legitimate place. If your garage has a pipe, a duct or a low ceiling running across the header, there may be no room for a torsion shaft, and a properly cabled extension setup is the correct answer.
Can you convert extension to torsion?
Usually yes, on a standard sectional door, and it is a common upgrade when an old extension setup is due anyway.
You need headroom, around 12 inches between the top of the door and the ceiling for a standard torsion tube, less for a low headroom kit. The conversion adds the shaft, bearings, drums, new cables and the springs sized to your door weight, so it costs more than swapping like for like. The tech will weigh the door or calculate from the panel construction, because springs sized by eye are the most common cause of a door that will not hold halfway.
Where headroom is genuinely tight, a low headroom torsion conversion or a rear mount torsion kit can still work. It is a measurement question and takes two minutes on site.
What does a healthy spring look like?
Worth knowing whichever type you have.
- No gap in the coils of a torsion spring. A gap of an inch or two means it is broken.
- No rust bleeding out between the coils.
- An extension spring that returns to a consistent closed length when the door is up.
- Both sides of an extension setup stretching by the same amount as the door moves.
- The door holds at waist height on its own with the opener disconnected.
- A safety cable visible through each extension spring.
Never try to adjust, unwind or re-tension a spring yourself, whichever type it is. There is no safe way to bleed that energy off without winding bars and the training to use them, and a slip happens at face height.
What to do with this
If you now know which type you have, you are ahead of most callers. Tell us the type, the door width and whether the door is insulated, and we can usually bring the right parts on the first trip. Our spring replacement page covers sizing, cycle ratings and what the visit includes.