
Springs · Toronto
Extension Spring Replacement
You pulled the red cord to open the door during a power cut and it barely moved. Lifting it took your whole weight, and when you let go it came down hard.
Extension Spring Replacement
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 goesThe home inspector's report on the house you are buying flags the garage door: extension springs with no safety cable running through them, coils showing rust, and a door that sank when he lifted it partway. The seller has never had it looked at.
Toronto
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.
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 door that lifts as it was designed to
The difference is felt the first time you pull the release cord and lift the door yourself. It rises with one hand, pauses where you leave it, and comes down at the speed you lower it rather than dropping the last stretch. Under power, the opener runs without the strain in its note that had crept in as the old springs tired, and the door reaches the floor evenly along the seal. Both springs now stretch to the same length as the door closes, both pulleys turn without a squeal, and the cables lie in their grooves. A door in this condition puts little wear on the opener, which is good news for the motor.
Extension Spring Replacement
In the van
- Door-weighing scale
- Bottom brackets and clevis pins
- Rear spring hangers and angle iron
- Lag screws and hanger bolts
- Lift cables
What affects the quote
Same fees day, night or weekend
1Hangers and anchor points
A rear hanger that has loosened, a front bracket bent by a jumped cable, or framing that needs a new anchor point adds fasteners, angle iron and a little time.
2Door weight and size
Spring rating follows the door's weight, and a wide insulated door or a wood door takes heavier springs than a light single. Weight and height together set the parts on the quote.
3Pulleys 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.
Extension Spring Replacement: questions
Why does the opener get adjusted after new springs?
Because the door is now much lighter for the opener to move. Over the years, as the old springs weakened, the opener's force setting may have been turned up to keep the door going, and its travel limits were set against a door that sat differently on the floor. Left alone, that extra force would push the newly balanced door too hard. Resetting force and travel, then repeating the reversal tests, matches the opener to the door it now has.
What can I do to make the new springs last?
Three things. Spray the springs, pulley axles and hinges with a garage-door lubricant twice a year, which slows rust in an unheated garage. Keep the threshold clear of bins and packed snow so the door never stops short with the springs still pulling. And leave the opener's force setting where the technician put it, since a door that starts needing more push is a balance question rather than a dial to turn.
Do 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.
Springs & Hardware

- Garage Door Hinge ReplacementPressing a hand against one of the middle hinges makes it rock on the panel.
- Garage Door Track Repair or ReplacementYou bought the house with a door that sticks near the top of its travel.
- Garage Door Cable ReplacementThe cable has wrapped itself around the shaft above the door instead of sitting on its drum.
Extension Spring Replacement near you
Residential and commercial customers in Toronto come to us for spring and cable replacement, off-track resets, opener diagnosis and replacement, remote and keypad programming, weatherstrip and seal work, balance adjustments, panel repair and new door installation. Each service is explained on its own page in plain language.