

Springs · Phelpston
Extension Spring Replacement in Phelpston
A bang like a dropped toolbox came from the garage last night.
In plain words
Extension springs are common on the detached garages behind older houses, where a low ceiling left no room for a torsion shaft, and those garages are rarely heated. Damp summers, hard frosts and salt carried in on the car pit the spring wire over the years, and a fatigued spring most often lets go on a cold morning when the steel is stiffest. Replacement fits a new pair rated for the door, renews the pulleys and cables that have rusted alongside them, adds containment cables where the original installation never had any, and leaves a door that lifts easily by hand when the power is out.
How the visit goesThe opener groans on the way up and the door slams the last foot on the way down, hard enough to rattle the windows. The motor is the same one it always was; something in the springs has stopped doing its share.
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.
Taking the old springs down
With the door open and clamped, each old spring is nearly slack, and removal is straightforward. The technician unhooks the lift cable from its S-hook or clip at the front, which lets the spring's pulley end drop free, then lifts the rear loop off the hanger. The old containment cable is unclipped from its anchors and pulled out of the coil. On a door with a broken spring, the two halves are gathered and the containment cable, if there was one, is inspected for the marks of having done its job. Everything that comes down is laid out on the floor so the old spring can be measured against its replacement and you can see the wear.
Checking the balance yourself
You can confirm the springs are still doing their share without going near them. With the door closed and nobody in the opening, pull the opener's red release cord so the trolley lets go of the door. Lift the door by its handle to roughly hip height and take your hands away. A door on good springs stays about where it is; if it sinks to the floor the springs have weakened, and if it rises on its own they are pulling harder than the door weighs. Either way it is a call rather than a job for you. Reconnect the opener the way your manual describes, usually by running it once.
Extension Spring Replacement
In the van
Lag screws and hanger bolts
Containment (safety) cables
Extension springs, matched pair
Replacement rollers and hinges
Track clamps or locking pliers

Extension Spring Replacement
What affects the quote
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.
Weight added since the door went in
Insulation panels, windows or a wood overlay fitted after the original springs mean a heavier rating than the old pair. The door is weighed and the quote reflects the door as it is now.
Converting to torsion instead
Where the garage has the headroom, some owners take the opportunity to move to a torsion system. That is a different job with different hardware and is quoted as its own option.
What to have ready
- Is a car parked inside that will need to come out first?
- Do you know how old the springs are or when they were last changed?
- Is the door closed, fully open, or stuck partway?
Extension Spring Replacement: questions
QuestionsHow do you know which springs my door needs?
By weight. Extension springs are rated for the weight they lift, so the technician releases the opener and weighs the door on a scale, then matches that figure and the door's height to a spring rating and stretch length. The old springs are measured as a check on wire size, coil diameter and length. Where the two disagree, the scale decides, since doors gain weight from added insulation or panels.
What is a safety cable, and does my door need one?
A safety or containment cable is threaded down the inside of each extension spring and fixed at the hanger behind and the bracket in front. It carries no load in normal use. If a spring snaps, the cable keeps the broken halves in place beside the track. Every extension-spring door should have one each side, and the industry's inspection checklist asks for it. Doors installed decades ago often have none; they are added with the new springs.
Would a stronger spring make the door easier to lift?
Not in a useful way. The aim is a spring that matches the door's weight, so the door holds still wherever you leave it. A spring rated above that weight pulls the door up on its own, makes it hard to close, and leans on the opener to hold it down. A spring rated below lets it sink. Matched springs, set to the same hook position, give the light, even feel you want.
Related services

- Garage Door Hinge ReplacementWatching from inside as the door opens, you can see the gap between the second and third panels open up on one side as they turn the corner into the ceiling, then close again.
- Garage Door Track Repair or ReplacementHalfway up, the door lurches and one roller rides onto the lip of the channel.
- Garage Door Cable ReplacementSomeone left the snow shovel leaning in the opening and the door came down on it.