

Springs · Brant
Extension Spring Replacement
The door climbs with the left corner ahead of the right, then twists as it turns into the ceiling track.
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 goesYou 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. It used to float up with one hand.
Extension Spring Replacement
How the visit goes


Securing the door with the springs slack
An extension spring is stretched tight when the door is closed and nearly relaxed when the door is fully open, so the first move is to get the door up. The technician pulls the opener's release, raises the door by hand if it will go, and clamps both vertical tracks below the bottom rollers so the door cannot come down. If a broken spring has left the door stuck partway, it is lifted and supported with the weight taken on clamps and props before anything else is handled. With the door held open, the springs, pulleys and hooks can be examined and removed like ordinary hardware, which is the whole reason the sequence begins this way.
Renewing the hardware around the springs
Anything the inspection flagged is dealt with while the door is open and the springs are slack, because that is when the work is easiest and the parts are already in hand. A pulley with a grooved wheel or a stiff bearing is swapped for a new one on its fork or bracket. Lift cables with rust at the loop or broken strands are replaced along with the springs. A rear hanger that had loosened is re-fixed with lag screws into a sound joist, and a bent front bracket is straightened or renewed. Bottom brackets eaten by salt and rollers with cracked wheels are changed at the same time.
Lubrication that keeps the new set turning
Twice a year, in spring and before winter, a can of garage-door lubricant does most of the maintenance the springs need. Spray a light coat along each extension spring, working from the hanger to the pulley; it slows rust in a damp garage and quiets the coils. Put a drop on each pulley axle and on the bolts through the pulley forks, then on the hinge pins and roller stems. Leave the tracks dry and wipe them clean, since grease there collects grit and stops rollers rolling. Heavy grease and general-purpose oil are avoided on the springs because they hold moisture against the wire. Run the door a few times afterwards to spread the film.
Extension Spring Replacement
In the van
Door-weighing scale
Rear spring hangers and angle iron
Lag screws and hanger bolts
Garage-door spray lubricant
Track clamps or locking pliers

Extension Spring Replacement
What affects the quote
Track or section damage found on the way
A bent horizontal track, a bracket pulled off the jamb or a top section twisted by running the opener on a broken spring is separate repair work, quoted on its own.
Hangers 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.
Corroded fasteners
In an unheated garage the bolts through pulley forks and hanger brackets rust solid; freeing or cutting them and fitting new hardware takes time and shows in the parts list.
What to have ready
- Is a spring broken in two, hanging loose, or just looking stretched?
- Has insulation, glass or a wood facing been added to the door?
- Is there a thin cable running through the middle of each spring?
Extension Spring Replacement: questions
QuestionsWhat information helps when I call?
Whether the springs run along the tracks or sit above the door; whether one is broken, hanging loose or just looks stretched; whether the door is closed, open or stuck partway and level or crooked; roughly how wide and tall the door is and what it is made of; and whether there is a cable running through each spring. A photo taken from inside with the door closed answers most of that at once.
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.
Could I switch to torsion springs instead of replacing the extension ones?
Sometimes, and it is worth asking. A torsion system needs room above the door opening for its shaft and a header that can carry the spring bracket, which many older garages with a low ceiling simply lack; extension springs are there for that reason. Where the headroom exists, a conversion is a separate job with its own hardware and quote. The technician can tell you on the spot which route suits your garage.
Related services

- Garage Door Hinge ReplacementPressing a hand against one of the middle hinges makes it rock on the panel.
- Garage Door Track Repair or ReplacementThe garage floor has settled at one corner, and the door now scrapes the concrete on that side while daylight shows at the other.
- Garage Door Cable ReplacementThe cable has wrapped itself around the shaft above the door instead of sitting on its drum.