Both systems counterbalance the door. Their position, related hardware, inspection points, and replacement requirements are different.
A common torsion setup mounts one or more springs on a shaft above the door. Cable drums at the ends of the shaft wind the lift cables as the door rises. The exact spring wire, inside diameter, length, wind direction, drum, shaft, and door weight all matter.
A visible gap in a previously continuous spring often indicates a break. Do not touch the spring, set screws, winding cone, cable drum, or bottom bracket.
Extension springs commonly run beside the horizontal tracks and stretch as the door closes. Pulleys, lift cables, spring anchors, and safety containment cables are part of the system.
A hanging spring, loose pulley, slack cable, or missing safety cable needs professional inspection. Keep clear of the door and do not try to reconnect the hardware.
A cycle is one complete open-and-close operation. Spring manufacturers offer different cycle ratings, but the rating applies only when the spring is correctly selected and installed for the actual door. Door weight, track setup, spring geometry, corrosion, damage, use, and balance can change real service life.
Do not convert a cycle rating into a guaranteed number of years. A busy shared door uses cycles much faster than a lightly used private garage. The written estimate should identify the proposed spring and explain any higher-cycle option that is actually compatible.
Door size alone does not settle this question. The door weight, drum and track setup, available shaft space, spring design, and manufacturer requirements determine a correct layout. On an existing two-spring system, both springs should be inspected because they work as a pair.
A spring stores enough energy to cause severe injury. Do not loosen set screws, move cable drums, remove bottom fixtures, stretch an extension spring, or use improvised tools. If the door is heavy, crooked, stuck, or has a loose cable, stop operating it.
A professional spring repair includes identification, correct sizing, related hardware inspection, installation, door balance, travel, and opener safety checks. A torsion conversion may be an option for some extension-spring doors, but only after the opening, track, door weight, and mounting structure are checked.
Call (551) 279-6408 with a photo taken from a safe distance. Literally Garage Door serves our nine-county Northern New Jersey service area and provides a free estimate before approved work begins.