

Springs · Toronto
Extension Spring Replacement
The opener groans on the way up and the door slams the last foot on the way down, hard enough to rattle the windows.
In plain words
What you have afterwards is a door that behaves like a much lighter object. Both corners leave the floor together, the door holds still when you stop it at waist height, and it settles onto the floor instead of slamming. The opener runs quietly, because it is guiding a balanced door rather than hauling a heavy one, and its safety reversing works as designed. Both springs are new, both carry a containment cable, the pulleys turn freely and both S-hooks sit in the same hole. You also get the spring rating and door weight written down, so the next set can be ordered without measuring everything again.
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


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.
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 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
Lift cables
Pulleys (sheaves) and forks
Replacement rollers and hinges

Extension Spring Replacement
What affects the quote
One spring per side or two
Heavier doors sometimes carry a pair of springs on each side rather than one. Four springs, four containment cables and the extra setting time show as their own lines.
Time of the call
An evening, weekend or holiday visit costs the same amount as a weekday daytime appointment for an extension-spring replacement. The technician confirms the exact figure once the springs, cables and door weight have been checked on site.
Containment cables to add
A door that never had containment cables gets them with the new springs, along with anchor hardware into the framing. It is a small parts line and a worthwhile one.
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?
- Does the door drop the last bit, or drift up on its own?
Extension Spring Replacement: questions
QuestionsShould I try to open the door by hand before the technician arrives?
No need, and it is easier on the door if you leave it. With a spring broken or slack, the door is unbalanced and heavy, and lifting it can let it drop or twist a section in the track. If the door is stuck partway, leave it there and keep people and the car away from the opening. The technician brings clamps and props, and the door is secured before it is moved at all.
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.
What is the difference between extension springs and torsion springs?
They balance the door in different places. Extension springs are the two long coils that run beside the horizontal tracks and stretch as the door closes; they work through pulleys and cables. A torsion spring is wound on a shaft above the door opening and turns drums that wind the cables. The parts, the way tension is set and the service itself are different, so it helps to say which you have when you call.
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 ReplacementStanding inside with the door closed, you notice the cable on the right side near the floor has gone fuzzy.