

Springs · Mount Vernon
Extension Spring Replacement in Mount Vernon
The door climbs with the left corner ahead of the right, then twists as it turns into the ceiling track.
In plain words
Extension springs are the two long coil springs that run beside the horizontal tracks of a garage door, one on each side. They stretch as the door closes and pull back as it opens, and that pull is what makes a heavy door feel light. Replacement puts a new, matched pair on the door. The technician opens and secures the door so the springs are slack, removes the old set, fits springs rated for the door's actual weight with containment cables through their centres, threads the lift cables over the pulleys, and adjusts both sides until the door balances. The opener is reconnected and tested last.
How the visit goesIt is the first hard frost of the year and the door on the old detached garage has stopped halfway, squealing at one pulley. The springs are the ones that came with the door decades ago, orange with rust where they hang near the back wall.
Extension Spring Replacement
How the visit goes


Containment cables, present or missing
The question the industry's own inspection checklist asks of every extension-spring door is whether each spring has a cable running through its centre, anchored at both ends. The technician checks for it on both sides, then checks its condition: a cable that is frayed, kinked, anchored to a loose screw or simply tied off to the hanger is not doing its job. Doors installed decades ago often have none at all, and doors that had a spring changed by a previous owner sometimes have one side fitted and one forgotten. Fresh containment cables go on with the new springs, and their anchor points are set into solid framing so that a spring which breaks stays on its cable.
Fitting a pair that matches the door
The new springs are selected from the door's measured weight and its height, which together give the rating and the stretched length required, and they are fitted as a pair even if one old spring looked sound. The technician checks each new spring's wire size, coil diameter and relaxed length against the specification before it goes up, and confirms the end loops suit the hanger and the pulley fork. The rear loop is hung on the hanger and the front loop takes the pulley fork. On heavier doors that carry two springs per side, all four are renewed together. Nothing is hooked to the door yet; the springs simply hang in place, slack, waiting for the cables.
A clear threshold and an honest opener
Two habits protect the new springs from the shocks that shorten a spring's life. The first is the floor: a door that comes down on a bin, a bike wheel or a ridge of packed snow stops short while the springs and cables are still pulling, and the jolt can throw a cable off its pulley. Keep the opening clear and scrape the ice ridge off the threshold before running the door in winter. The second is the opener's force setting. It was set for the newly balanced door; if the door ever seems to need more push, that is the springs asking for attention, not a reason to turn the force up.
Extension Spring Replacement
In the van
Door-weighing scale
Rear spring hangers and angle iron
Lag screws and hanger bolts
Garage-door spray lubricant
Track clamps or locking pliers

Extension Spring Replacement
What affects the quote
Pulleys that need renewing
Each side has two pulleys, and a wheel worn to a groove or a bearing that has stiffened is replaced with the springs. The quote names how many and which type.
Corroded fasteners
In an unheated garage the bolts through pulley forks and hanger brackets rust solid; freeing or cutting them and fitting new hardware takes time and shows in the parts list.
Opener adjustment and testing
Resetting the opener's force and travel to the newly balanced door and running the reversal tests is a short task that the quote names when it applies.
What to have ready
- Is there anything stored beside the tracks or under the springs?
- Do you know how old the springs are or when they were last changed?
- Does one corner of the door hang lower than the other?
Extension Spring Replacement: questions
QuestionsWhat information helps when I call?
Whether the springs run along the tracks or sit above the door; whether one is broken, hanging loose or just looks stretched; whether the door is closed, open or stuck partway and level or crooked; roughly how wide and tall the door is and what it is made of; and whether there is a cable running through each spring. A photo taken from inside with the door closed answers most of that at once.
Only one spring broke. Why replace both?
The two springs are the same age and have stretched the same number of times, so the one still hanging is close behind. There is also a balance reason: a door lifts level only when both sides pull equally, and a new spring beside a worn one lifts its corner first and twists the door. Fitting a matched pair sets both sides the same and avoids a second visit a few months on.
Could I switch to torsion springs instead of replacing the extension ones?
Sometimes, and it is worth asking. A torsion system needs room above the door opening for its shaft and a header that can carry the spring bracket, which many older garages with a low ceiling simply lack; extension springs are there for that reason. Where the headroom exists, a conversion is a separate job with its own hardware and quote. The technician can tell you on the spot which route suits your garage.
Related services

- Garage Door Hinge ReplacementPressing a hand against one of the middle hinges makes it rock on the panel.
- Garage Door Track Repair or ReplacementThe garage floor has settled at one corner, and the door now scrapes the concrete on that side while daylight shows at the other.
- Garage Door Cable ReplacementThe cable has wrapped itself around the shaft above the door instead of sitting on its drum.