

Springs · Stouffville
Extension Spring Replacement in Stouffville
One of the springs beside the track is hanging loose at the front end, its pulley dangling, and a length of cable lies slack along the top of the door.
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 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.
Extension Spring Replacement
How the visit goes


Hangers, brackets and what they are screwed into
Extension springs pull against whatever holds their back end, usually an angle-iron hanger bolted to the rear track support or lag-screwed into a ceiling joist. The technician checks that this anchor is tight, that the lag screws bite into wood rather than drywall or a split joist, and that the hanger has not bent under years of load. The bracket that carries the fixed pulley at the front of the track is checked the same way, along with the bottom brackets on the door that the lift cables pull on. An anchor that has loosened lets the spring's geometry drift, which is one reason a door slowly becomes uneven.
Running the lift cables
Each lift cable starts at the bottom bracket, where its loop goes over the pin or is secured with a clevis pin. From there it runs up the vertical track, over the fixed pulley at the front of the horizontal track, back along the track to the pulley on the end of the spring, around it, and forward again to the S-hook or adjusting clip at the front hanger. The technician keeps the cable seated in each pulley groove and makes sure it passes on the correct side of the containment cable and the track. Cables are renewed if the old ones showed any fraying or rust, and always as a pair of the same length.
Containment cables, and leaving them be
Your door now has a cable running through the middle of each spring, anchored at the back hanger and at the front of the track. It carries no meaningful load while the springs work, though a trace of slack as the door cycles is normal. Its job begins only if a spring ever breaks, when it holds the pieces on the cable instead of letting them fly. It should not be removed, used to hang anything, or tied back to the wall. If it ever looks badly slack, frayed or pulled from its anchor, call to have it corrected promptly rather than waiting for a routine visit. A home inspector looks for this cable when a house is sold.
Extension Spring Replacement
In the van
Lag screws and hanger bolts
Track clamps or locking pliers
Pulleys (sheaves) and forks
Bottom brackets and clevis pins
Garage-door spray lubricant

Extension Spring Replacement
What affects the quote
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.
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.
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.
What to have ready
- Does one corner of the door hang lower than the other?
- Is a car parked inside that will need to come out first?
- Is a spring broken in two, hanging loose, or just looking stretched?
Extension Spring Replacement: questions
QuestionsWhy 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.
Only one spring broke. Why replace both?
The two springs are the same age and have stretched the same number of times, so the one still hanging is close behind. There is also a balance reason: a door lifts level only when both sides pull equally, and a new spring beside a worn one lifts its corner first and twists the door. Fitting a matched pair sets both sides the same and avoids a second visit a few months on.
What happens during the visit?
The technician releases the opener, opens the door fully and clamps it so the springs go slack, then inspects springs, pulleys, cables, hangers and containment cables and weighs the door. The old springs come off, a matched pair goes on with containment cables through them, the lift cables are routed over the pulleys and the two sides are set to matching hook positions. The door is balanced by hand, the opener reconnected and its reversing tested with you watching.
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 ReplacementAfter years of slushy winters the cables look thinner near the bottom brackets, with rust streaks running down the door where they attach.