Garage Door Extension Spring Replacement in St. Louis
Worn extension springs replaced in pairs with proper safety cables, so the door lifts evenly and stays safe if a spring lets go.
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Extension Springs Work Differently Than Torsion Springs
Extension springs run along the horizontal tracks on either side of the door and stretch as the door closes, rather than winding around a shaft above the opening the way torsion springs do. They are common on older garages across the St. Louis area, particularly in established neighborhoods like Kirkwood and Webster Groves where many homes still have their original hardware. Extension springs typically wear out in pairs, and a door running on one weak spring and one strong one tends to close crooked or jerk to one side partway through the cycle.
Because an extension spring stretches under load, a snapped spring can whip with real force if it is not restrained. Every extension spring we install is fitted with a safety cable that runs through the spring's coil and anchors at both ends, so a broken spring stays contained instead of becoming a hazard. If your garage actually uses torsion springs mounted on a shaft above the door, that is a different repair covered on our garage door spring replacement page, and it helps to know which type you have before calling for service.
We replace both springs together, check the safety cables, and test the door's balance before finishing the visit.
What's Included in an Extension Spring Replacement
Springs Replaced in Pairs
Both extension springs are replaced together so the door lifts evenly on each side instead of pulling crooked.
Correct Spring Rating
Springs are matched to the door's weight and cycle rating, since an undersized spring shortens the life of the opener too.
Safety Cable Installation
A safety cable is run through each spring and anchored at both ends so a future failure stays contained.
Pulley and Cable Inspection
The pulleys and lift cables that work with the extension springs are checked for fraying or wear at the same visit.
Balance and Travel Testing
After the new springs are set, we test the door's balance and full travel to confirm it opens and closes smoothly.
Springs Replaced, Doors Running True
"One spring had snapped and the other was clearly close behind. They replaced both and added safety cables I didn't even know were missing on the original setup."
"Door was closing crooked for weeks before I called. Turned out to be a classic mismatched spring pair. Runs smooth now."
Extension Spring Questions, Answered
Can you replace just one extension spring, or do both need to change?+
Technically only the broken one has to be swapped, but we recommend replacing both since they wear at a similar rate and a mismatched pair causes the door to close unevenly within a short time. Replacing both in one visit also means one trip instead of two.
How common is it for a garage door spring to break?+
Extension springs have a rated cycle life, typically several thousand open-and-close cycles, and normal daily use wears them down gradually until one lets go, often without much warning. Homes that use the garage door as a main entrance tend to reach that wear point faster.
Are garage door safety cables easy to replace, and are they necessary?+
Safety cables are a straightforward add during a spring swap, and they are worth having on every extension spring setup. Without one, a snapped spring can whip loose with enough force to damage the track or injure someone nearby.
What should I do if my garage door cables or springs are broken?+
Stop using the door and avoid forcing it manually, since a broken spring changes how much weight the cables and track are handling. We offer same-day service for broken springs and can usually get a technician out the same day the call comes in.
Is it worth repairing a broken extension spring instead of replacing the whole door?+
In almost every case, yes. A spring failure does not mean the door itself is damaged, and replacing the spring pair and safety cables typically restores normal operation. We give a free, upfront quote so you can weigh spring replacement against any other repair needs before deciding.
Dealing With a Broken or Mismatched Spring?
Describe what the door is doing and we'll get you a same-day appointment and a clear plan before any work starts.
Serving St. Louis
Garage Doors Spring Works Co provides fast, same-day garage door repair, installation, and service across St. Louis and the surrounding Orange County communities. Licensed, bonded, and insured, with technicians who call ahead.