Why the door falls after you open it
A garage door that opens but refuses to stay up has lost its counterbalance. The door itself weighs 150 to 300 pounds. Springs carry that weight. When they can’t, the door drops — sometimes slowly, sometimes all at once. In Richmond, we see this most often on double doors in Steveston and Broadmoor homes built in the 1980s and 1990s where the original torsion springs are past their rated cycles.
The three components that hold the door up
Torsion springs sit on a steel shaft above the door. They wind and unwind to offset the door’s weight. A properly sized pair on a standard 16-foot double door stores enough torque to hold the door at any height. When a spring loses tension — metal fatigue, a crack, or a clean break — the door becomes heavy. You’ll hear a loud bang if it snaps. If it just weakens, the door drifts down within seconds of opening.
Extension springs run along the horizontal tracks on lighter, older single doors. They stretch to provide lift. When one stretches permanently or breaks, the door pulls crooked and won’t stay level. Both springs should be replaced as a pair; mismatched tension twists the door and ruins rollers.
Cables attach to the bottom brackets and wind onto drums (torsion) or run through pulleys (extension). A frayed or slipped cable removes tension from one side. The door cocks sideways, binds in the tracks, and slides down. You’ll often see loose cable loops on the floor or a drum that’s spun loose on the shaft.
How to tell which part has failed
Test 1: Manual lift. Pull the red emergency release cord. Lift the door by hand to waist height and let go. A balanced door stays put. If it drops, the springs aren’t carrying the weight. If it shoots up, they’re over-tensioned — rare, but it happens after a DIY adjustment gone wrong.
Test 2: Visual spring check. Look at the torsion springs above the door. A healthy spring is a tight coil with no gaps. A broken spring shows a clean gap of two to three inches between coils. Rust streaks or powdered metal on the shaft mean the spring is cracking internally.
Test 3: Cable inspection. With the door closed, run your fingers along each cable from bottom bracket to drum. Fraying, kinks, or slack on one side means that cable has lost tension. Do not pull on a loose cable — the spring tension behind it can snap your hand into the drum.
Test 4: Track binding. Watch the rollers as the door moves. If they skip, squeal, or the door shudders, the tracks may be bent or the rollers worn flat. Binding steals the spring’s lifting force. The door feels heavy at the bind point, then drops once past it.
How to check garage door springs and cables safely
- Photo-eyes. Clean the lenses with a dry cloth. Misaligned sensors won’t cause a door to fall, but they’ll reverse it before it reaches the floor — which feels like “won’t stay open” if the door never finishes opening.
- Opener force settings. If the door opens with the wall button but drifts down after the opener stops, the opener’s up-force may be set too low. Consult the manual; adjustment is a small screwdriver turn on the motor unit.
- Roller condition. Nylon rollers with cracked tires or steel rollers frozen in their stems add drag. Spin each roller by hand with the door closed. They should turn freely.
- Lubrication. Dry springs and rollers increase friction. A light coat of PTFE spray on spring coils and roller stems (not the track) can recover a few pounds of lift — enough to test, not to fix.
Stop there. Everything beyond this point involves stored energy that can kill you.
Where DIY ends and the tech takes over
Torsion spring replacement. The spring is wound to 300–400 inch-pounds of torque. Winding bars, a solid vise grip on the shaft, and a precise turn count are the only things between you and a steel bar spinning at shin height. We carry calibrated winding bars and replace springs in matched pairs, cut to the door’s exact weight and height. Guessing the wire size or inside diameter by eye is how you get a door that’s heavy on one side and light on the other.
Cable replacement on a live torsion system. You cannot safely remove a cable while the spring is wound. The spring must be unwound first — same hazard as above. Then the drum comes off, the cable threads through the bottom bracket, and the whole assembly is re-tensioned. If the bottom bracket is bent from the cable slipping, that bracket gets replaced too. It’s the anchor point for all lifting force.
Extension spring conversion. Some older Richmond homes in Terra Nova still run extension springs with open pulleys. We convert them to torsion. Safer, smoother, longer life, and the springs sit out of the way above the door instead of alongside the tracks where a car bumper can hit them.
Track realignment. Bent horizontal tracks or a shifted vertical jamb change the door’s geometry. We loosen the lag bolts, square the tracks to the door, shim where the foundation has settled, and re-torque. Richmond’s clay soil moves. A door that worked for twenty years can bind after a wet winter shifts the header.
What a broken garage door spring repair costs
- Spring size and cycle rating. Standard 10,000-cycle springs cost less. High-cycle (25,000+) springs use thicker wire and more coils — better value if you plan to stay in the house.
- Single versus double spring. Most 16-foot doors need two springs. Replacing one saves nothing; the mate will fail within months.
- Cable and drum condition. Drums strip, cables fray. If they’re worn, they’re replaced during the spring job. Doing it later means paying for the same labour twice.
- Opener compatibility. If the opener’s force limits need reprogramming after spring replacement, that’s included. If the opener is too old to handle the new spring torque, we’ll tell you before you approve the job.
Keeping it open next time
Cycle count matters more than years. A spring rated for 10,000 cycles lasts seven years at four cycles a day. Two cars, two adults, kids’ bikes — that’s eight cycles. Now it’s three and a half years. High-cycle springs shift the math.
Lubricate the springs twice a year. PTFE spray on the coils in spring and fall. Wipe excess. Do not use WD-40; it strips the factory coating and attracts grit.
Watch the cables. Fraying starts at the bottom bracket where the cable bends. Catch it early and you replace a $15 cable instead of a $400 spring-and-cable job after the cable snaps and the spring unwinds violently.
Test balance monthly. Pull the release. Lift to waist height. Let go. If it moves more than a few inches, call before the opener burns out trying to lift a heavy door.
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