

Springs · Toronto
Extension Spring Replacement
Open the door by hand and it drifts back down on its own, a little at first and then all at once.
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 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


Both springs, side by side
Even when only one spring has snapped, both are read closely. The technician looks for gaps opening between coils with the door up, which means the wire has stretched and lost its pull; rust pitting and scale, especially where the spring sits nearest the back wall; a spring hanging visibly longer or lower than its partner; and end loops that have opened or cracked. The two are compared for length, coil diameter and wire size, because springs of different ratings are sometimes found on the same door after a past repair. Whatever is found, the outcome is the same, a new matched pair, but the reading tells the technician what rating the door really needs.
Threading the containment cables
Before a spring is hung, a containment cable is fed through the centre of its coil. One end is anchored at the rear, to the hanger or the framing behind it, and the other is run forward past the pulley and fixed to the bracket at the front of the track or to the wall, with enough slack that the cable never carries load while the spring works. The cable is checked to be clear of the pulley wheel and the lift cable so nothing rubs. Both sides are done the same way, whether or not the old installation had them. A spring that breaks in future is held on the cable rather than crossing the garage.
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
Lift cables
Containment (safety) cables
S-hooks and adjusting clips
Pulleys (sheaves) and forks
Rear spring hangers and angle iron

Extension Spring Replacement
What affects the quote
Working room around the springs
Shelving, a stored canoe or a car parked under the tracks slows the work along the horizontal run. Clearing the sides of the garage beforehand keeps the time on the quote short.
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.
How the door is sitting
A door resting closed with one spring gone is straightforward. A door stuck partway, twisted in its tracks or with a cable wrapped around a pulley has to be supported and straightened first.
What to have ready
- Do you know how old the springs are or when they were last changed?
- Does the door drop the last bit, or drift up on its own?
- Is the door closed, fully open, or stuck partway?
Extension Spring Replacement: questions
QuestionsCan I keep using the opener until the spring is replaced?
It is better to leave the door where it is. With one spring gone, the opener is lifting most of the door's weight on its own, which strains the motor, can bend the top section and often throws a cable off its pulley, adding to the work. Use another door in and out, keep the bay clear, and let the technician move the door once it is secured.
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.
What does the paint colour on the end of the spring mean?
Manufacturers dab a colour on the end coil to indicate the spring's weight rating, which is a handy starting point. It is not the final word: a faded or repainted end coil tells you little, and the pair on an older door may have been a near match rather than the right one. The technician treats the colour as a hint and confirms the rating from the door's measured weight and the spring's own dimensions.
Related services

- Garage Door Hinge ReplacementAfter a cold night the bottom seal had frozen to the slab.
- 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.