Torsion Spring — counterbalance spring over garage door

A torsion spring is the coiled steel spring mounted above a garage door that stores energy and helps lift the door's weight.

What It Is

A torsion spring winds around a shaft at the garage door header. As the door closes, the spring tightens and stores energy. As the door opens, that stored energy helps turn the shaft and lift the door through the cable drums.

This counterbalance system is what makes a heavy garage door feel manageable. When a torsion spring breaks or loses tension, the opener strains and the door can become extremely heavy and unsafe to lift.

Types

Common types include standard torsion springs, oil-tempered springs, galvanized springs, left-wind springs, and right-wind springs. Some double-wide doors use a pair of springs sized to balance the full door weight.

Where It Is Used

Torsion springs are used on sectional garage doors and some rolling doors. They are mounted on the shaft directly above the door opening, usually centered over the header.

How to Identify One

Look above the closed garage door for one or two tightly wound metal coils wrapped around a horizontal shaft. A broken spring often shows a visible gap in the coil and may be accompanied by a loud bang when it fails.

Replacement

Replacement is needed when the spring breaks, loses balance, rusts badly, or no longer matches the door weight. Because the springs are under high stored tension, replacement is a high-risk repair best handled by a trained garage door technician.