

Springs · Brampton
Extension Spring Replacement
It is the first hard frost of the year and the door on the old detached garage has stopped halfway, squealing at one pulley.
In plain words
Every extension spring should carry a containment cable, and replacement is the moment to make sure yours do. A containment cable runs through the centre of the spring and is anchored at both ends, to the rear hanger and to the bracket at the front of the track. It does no lifting; its purpose is to hold a spring that breaks so the pieces stay on the cable. Many older doors predate this practice, which a home inspection checklist checks for. When springs are replaced, new containment cables are fitted with them, which keeps a broken spring's pieces contained, not the door's weight, balance or safety.
How the visit goesOpen the door by hand and it drifts back down on its own, a little at first and then all at once. Nothing is broken that you can see, but the springs along the tracks look tired, rusty and slightly sagging.
Extension Spring Replacement
How the visit goes


Pulleys, cables and the hooks that set them
Each side of an extension system has two pulleys, one on the moving end of the spring and one fixed at the front of the horizontal track, and a lift cable that runs from the bottom bracket over both to an S-hook or clip on the track hanger. Each pulley is spun to feel for a rough bearing and looked at for a wheel worn to a sharp groove or wobbling on its bolt. The cables are followed for fraying, rust at the bottom loop and a wrap that has slipped off a pulley. Worn pulleys and cables are renewed with the springs, since a seized pulley is often what shortened the old spring's life.
Balancing the door by hand
Balance is judged with the opener still disconnected. The technician lowers the door to the floor, then lifts it: it should rise with modest effort, stay put when let go at about waist height, sit steady when fully open, and come down under control rather than dropping. If it sinks, both springs need a little more stretch and each S-hook is moved one hole to take up cable; if it climbs on its own, one hole the other way. Adjustments are always made in pairs, with the door open and clamped again each time, so the two springs stay equal. Two or three rounds usually settle it.
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
Replacement rollers and hinges
Containment (safety) cables
Lift cables
Track clamps or locking pliers
Garage-door spray lubricant

Extension Spring Replacement
What affects the quote
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.
Getting the van to the garage
A detached garage down a shared laneway, a rural property or a building with the bay behind a gate takes more time to reach and set up in, and the quote allows for that.
Track or section damage found on the way
A bent horizontal track, a bracket pulled off the jamb or a top section twisted by running the opener on a broken spring is separate repair work, quoted on its own.
What to have ready
- Does the opener still move the door, and does it sound strained?
- Is there a thin cable running through the middle of each spring?
- Does one corner of the door hang lower than the other?
Extension Spring Replacement: questions
QuestionsDo the pulleys need replacing at the same time?
Often, yes. Each side has two pulleys, one on the spring and one fixed at the front of the track, and the cable rides over both on every trip. A pulley whose wheel has worn a sharp groove, or whose bearing has stiffened, drags on the cable and adds load the spring has to overcome, which is a common reason the old spring wore early. Pulleys that spin freely and run true can stay.
Why does the door slam down the last bit?
A door that drops the final stretch is telling you the springs are no longer holding it. As an extension spring loses its temper it gives less pull near the bottom of travel, where the door needs the most support, so the door falls that last foot. Fresh springs matched to the door's weight bring the door down under control and take that shock off the bottom section and the opener.
Can I use the door as soon as the work is done?
Yes. The last steps of the visit are the balance test by hand, several full cycles under power and the opener's reversal checks, so the door is ready for normal use when the technician leaves. New springs need no settling period. It is worth running it yourself once or twice while the technician is still there, so you know what a properly balanced door sounds and feels like from now on.
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 ReplacementAfter years of slushy winters the cables look thinner near the bottom brackets, with rust streaks running down the door where they attach.