

Springs · Conn
Extension Spring Replacement in Conn
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
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 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


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.
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.
Knowing when the next set is due
A standard extension spring is made for a set number of open-and-close cycles, commonly in the ten-thousand range, which on a door used four times a day works out to several years and on a door used twice a week to much longer. Springs age even when idle, as rust does its slow work in an unheated garage. The signs that the set is nearing the end are gradual: the door feels heavier by hand, the opener sounds as if it is working, the door drifts down from halfway, and gaps appear between coils when the door is open. Acting on those signs turns the next replacement into a planned appointment rather than a bang in the night.
Extension Spring Replacement
In the van
Containment (safety) cables
Lag screws and hanger bolts
Bottom brackets and clevis pins
Track clamps or locking pliers
Lift cables

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.
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.
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
- Do the springs run along the tracks beside the door, or is there one spring above the opening?
- Is the door closed, fully open, or stuck partway?
- Is a spring broken in two, hanging loose, or just looking stretched?
Extension Spring Replacement: questions
QuestionsWhy does the opener get adjusted after new springs?
Because the door is now much lighter for the opener to move. Over the years, as the old springs weakened, the opener's force setting may have been turned up to keep the door going, and its travel limits were set against a door that sat differently on the floor. Left alone, that extra force would push the newly balanced door too hard. Resetting force and travel, then repeating the reversal tests, matches the opener to the door it now has.
Should 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.
My springs squeak and twang. Is that normal?
Some noise is ordinary. Extension springs stretch and relax on every trip, and a dry coil or a pulley with a dry axle will squeak, especially in cold weather; a light spray of lubricant along the springs and a drop on each pulley usually quiets it. A sharper twang, or a new grinding from a pulley, is worth a look, since a stiff pulley loads the spring and wears the cable.
