

Springs · York Height
Extension Spring Replacement in York Height
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 goesA bang like a dropped toolbox came from the garage last night. This morning one of the long springs beside the track hangs in two pieces, and the door will only rise a few inches before the opener gives up and stops.
Extension Spring Replacement
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.
Bringing the opener back into step
The opener is the last thing touched. Once the door balances by hand, the trolley is reconnected and the door run through several full cycles under power while the technician watches the cables ride their pulleys and the springs stretch evenly. Because the door is now lighter to move than it was on tired springs, the opener's force and travel settings are reset to suit; a force setting left high would push a balanced door too hard. Then the reversal checks are done in front of you: a block laid flat under the centre of the door, which the door must touch and reverse from, and a hand passed through the photo-eye beam while the door closes.
The numbers that stay with the door
Before leaving, the technician tells you what the door weighed, which spring rating and length went on, whether the pulleys and cables were renewed, and which hook position the cables were set to. Write it on a card by the opener or inside the door's manual. Extension springs are sold by rating and length, so the next set can be ordered from that card without weighing the door again, and a technician arriving later can see at a glance whether the door has been altered since. Add the date and roughly how many times a day the door is used; together those two facts give a fair idea of when the springs will be due again.
Extension Spring Replacement
In the van
Replacement rollers and hinges
Bottom brackets and clevis pins
Pulleys (sheaves) and forks
Track clamps or locking pliers
Rear spring hangers and angle iron

Extension Spring Replacement
What affects the quote
Rollers, hinges and bottom brackets found worn
Cracked roller wheels, split hinges or a bottom bracket rusted at the cable pin are pointed out during the inspection and offered as optional items, since the door is already open and secured.
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.
Condition of the lift cables
Cables with fraying, rust at the loop or a kink are renewed as a pair while the springs are off. Sound cables are re-routed and set, and the quote says which applies.
What to have ready
- Do you know how old the springs are or when they were last changed?
- Is a spring broken in two, hanging loose, or just looking stretched?
- Do the springs run along the tracks beside the door, or is there one spring above the opening?
Extension Spring Replacement: questions
QuestionsCould 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.
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 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.
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