Torsion vs. extension garage door springs

Every sectional garage door uses springs to counterbalance its weight. There are two kinds, and which one your door has affects how long the springs last, how they fail, and what replacement costs.

How each type works

Torsion springs are mounted on a steel shaft above the door opening. As the door closes, the cables unwind from drums on the shaft and twist the springs tighter; as it opens, the springs unwind and turn the drums, lifting the door. Most residential doors have one or two.

Extension springs run parallel to the horizontal tracks, one on each side. As the door closes, they stretch; as it opens, they contract and pull the cables through pulleys to lift the door. They always come in pairs.

Side-by-side

	Torsion springs	Extension springs
Where	On a bar above the door	Along each horizontal track
Typical cycle life	10,000 – 20,000 cycles (about 8–15 years)	8,000 – 15,000 cycles (about 7–12 years)
Replacement cost	$75 – $150 per spring	$50 – $100 per spring
How many	One or two	Always two
When one breaks	Stays on the shaft	Can whip loose without a safety cable
Balance	Smoother, more even lift	More prone to a crooked lift if one side weakens
Common on	Most newer doors, heavier doors	Older doors, many single-car detached garages

Cycle and cost figures: HomeAdvisor, updated June 2026. One cycle is one open and one close.

Safety differences

Both types store a lot of energy and both are dangerous to adjust or replace without training. The difference is how they fail. A broken torsion spring stays on its shaft. A broken extension spring, if it has no safety cable through it, can fly across the garage. That’s why safety cables matter so much on extension-spring doors, and why many older Connecticut garages, especially detached single-car garages behind postwar capes and multi-family houses, are worth a look.

Converting from extension to torsion

HomeAdvisor prices an extension-to-torsion conversion at $400 to $800. It’s worth considering when:

• Both extension springs are worn out and need replacing anyway.
• The door is in good shape and you plan to keep it for years.
• The door lifts unevenly or the springs lack safety cables.

It’s less worthwhile on an old door with damaged sections or rot, where that money is better put toward a new door.

Getting the size right

Whichever type you have, the replacement must be sized to the door’s weight and height. The garage door industry’s DASMA technical guidance warns that a spring that doesn’t match the door’s counterbalance requirement shortens the life of the door and the opener, and that extra weight added to a door, such as insulation, can push it past what the original springs were sized for. A good technician measures or weighs the door rather than just matching the old spring.

For prices and red flags, see our spring replacement cost guide. For the repair itself, see garage door spring repair.