Broken Spring Repair in Dallas & the east metroplex

How a torsion spring stores and returns energy

A torsion spring sits on a steel shaft above the door opening. Installing it means winding it a specific number of turns, commonly around seven and a half for a seven foot door, which twists the spring steel and stores mechanical energy in it. Cables run from drums at each end of that shaft down to brackets at the bottom corners of the door. As the door closes, the door's own weight winds the spring tighter; as it opens, the spring unwinds and returns that stored energy to the drums, which pull the cables and lift the door. The system is designed so that the spring's torque and the door's weight cancel out, which is why a healthy door can be lifted with about ten pounds of hand effort despite weighing well over a hundred.

Why a broken one is dangerous to work on

The danger is not the broken spring, which has already released. The danger is everything else still under load. On a two spring door, the intact spring is still fully wound. The cables are still anchored to bottom brackets that are under the full tension of that counterbalance, which is why those brackets carry a warning label from the factory. Winding or unwinding a torsion spring is done with steel winding bars inserted into the holes of the winding cone; if a bar is the wrong diameter, if the set screws are not properly seated, or if a hand slips, the bar comes out of the cone at speed with several hundred pounds of torque behind it. Emergency departments see these injuries regularly, and they are typically hand, wrist, facial, and dental. Screwdrivers and lengths of rebar used in place of proper winding bars are how most of them happen.

Torsion and extension springs are different systems

Torsion springs mount on a shaft above the opening and are standard on most doors installed in the last few decades. Extension springs run horizontally along the tracks on each side, stretch as the door closes, and contract to help lift it. Extension springs are still common on older and lighter doors, and they carry a specific hazard: without a safety cable threaded through the center of the spring and anchored at both ends, a failing extension spring becomes a whipping length of steel across the garage. If your door has extension springs and no safety cables, adding them is inexpensive and we will recommend it whether or not the spring has failed.

Cycle life, and what the numbers actually mean

A cycle is one full open and one full close. Standard springs are commonly rated at 10,000 cycles. High cycle springs, built with heavier wire and greater length, are available at 20,000, 25,000, and higher ratings. The arithmetic is worth doing for your own household. A family using the garage as the main entrance easily runs six cycles a day, which is about 2,190 a year, which spends a 10,000 cycle spring in roughly four and a half years. A retired couple using it twice a day is looking at closer to fourteen years on the same spring. Neither is a defect. If your door failed early, the useful question is whether the spring was correctly sized for the door in the first place.

Why we replace both springs, not just the broken one

On a two spring door, both springs were installed on the same day and have taken the same number of cycles. When one reaches the end of its fatigue life, the other is within a short distance of the same point. Replacing only the failed spring gives you a door with one new spring and one old one, an unequal torque distribution across the shaft, and a second service call in the near future for the same problem. There is also a sizing consequence: springs are selected as a matched pair for the door weight, and a mismatched pair never balances the door correctly across its travel. Replacing both at once costs less than two visits and produces a door that actually balances.

Sizing is measurement, not estimation

A torsion spring is defined by four values: wire diameter, inside diameter, overall length, and wind direction. Those combine to determine how much torque the spring produces per turn. Selecting a replacement means knowing the door's weight, either by weighing it on a scale with the springs disconnected or by calculating from section construction, glazing, and hardware. A spring undersized for the door leaves the door heavy at the floor and burns cycles fast. A spring oversized for it leaves the door wanting to fly open and makes the opener fight it on the way down. Both feel roughly acceptable on the day of installation, and both shorten the life of everything they are attached to.