Our spring replacement cost guide covers pricing for both spring types — this article focuses on the differences between them, since knowing which system your door uses affects everything from safety considerations to repair approach.
How to Tell Which Spring Type You Have
This is easier than most homeowners expect. Look at your closed garage door from inside: if you see a single spring wound around a bar mounted horizontally right above the door opening, that's a torsion spring system. If instead you see springs stretched along the upper horizontal tracks on either side of the door (parallel to the tracks, extending and contracting as the door moves), that's an extension spring system. Most doors installed since the late 1990s use torsion springs, but plenty of older homes throughout Hudson Valley still have working extension spring systems.
Why the Difference Matters Beyond Just Location
| Factor | Torsion Springs | Extension Springs |
|---|---|---|
| Failure behavior | Contained by the mounting bar — less projectile risk | Can release with more force if safety cables aren't installed |
| Door balance | Generally more precise, smoother operation | Can develop slight unevenness over time as springs stretch unevenly |
| Typical install | Since ~1990s-present, most new doors | Common in homes built or last-updated before the 1990s |
| Safety cable requirement | Less critical due to contained design | Strongly recommended if not already present |
The Safety Cable Issue With Extension Springs
If your door uses extension springs, one important safety check often gets missed: is there a safety cable running through the center of each spring? This cable is designed to catch the spring if it snaps, preventing it from becoming a projectile. Many older installations, particularly ones done before modern safety codes, don't have these cables retrofitted. If you have extension springs and aren't sure whether safety cables are present, this is worth a quick professional check — it's a low-cost safety upgrade with real risk-reduction value.
Converting From One System to the Other
Some homeowners with older extension spring systems ask about converting to torsion springs during a repair, rather than waiting for a full door replacement. This is possible but involves more than just swapping the springs — it typically requires adding a torsion bar mount above the door opening, which some garages have adequate headroom and framing for and others don't. It's worth a professional structural assessment before committing, since the labor cost of a mid-repair conversion is meaningfully higher than simply replacing extension springs in kind, or waiting to make the switch as part of a full door replacement when the torsion hardware is included in that larger project anyway.
Repair Considerations by Spring Type
- Torsion spring replacement typically requires specific winding bars and precise calculation of wire size, coil diameter, and winding length
- Extension spring replacement is somewhat more straightforward mechanically, but proper safety cable installation is essential if not already present
- Both types should always be replaced in pairs (both springs) even if only one has failed, since the surviving spring is the same age and near the same failure point
- Neither type is a safe DIY repair — the mechanical tension involved is dangerous regardless of spring style
Common Homeowner Mistakes
Assuming extension springs are inherently unsafe rather than understanding that missing safety cables (not the spring type itself) create most of the added risk, and mixing spring types or sizes when only one fails rather than matching the existing system correctly.