Torsion Spring Replacement
Detailed procedure for removing failed torsion springs and installing new ones on residential and commercial sectional overhead doors. Covers pre-job assessment including spring identification and IPPT calculation, safe unwinding of existing springs, hardware inspection, installation of new springs, proper winding, door balancing, and operator reconnection. This procedure applies to standard torsion, EZ-SET, and commercial duplex torsion spring systems.
Warnings
This procedure must only be performed by trained, qualified door service technicians with specific experience in torsion spring systems. Improper spring handling causes multiple fatalities each year in the door industry.
Torsion springs store lethal energy. A spring unwinding unexpectedly can cause severe injury or death.
ALWAYS use properly sized winding bars. Never use screwdrivers, rebar, or other improvised tools — they can slip out of the winding cone.
Never stand directly in front of or behind the winding cone. Always position yourself to the side of the spring.
If a winding bar slips or you feel the spring is binding, stop immediately and reassess before continuing.
Always replace springs in matched pairs on a two-spring (duplex) system, even if only one spring has broken. The remaining spring has the same cycle count and is near the end of its life.
Required PPE
- Safety glasses (mandatory — rated for impact)
- Steel-toe boots
- Cut-resistant work gloves (remove when inserting winding bars into cone)
- Hard hat (commercial installations with high headroom)
- Long-sleeve shirt (arm protection from spring contact)
Tools Required
- Winding bars (2 — matched to cone size, typically 1/2 in. diameter x 18 in.)
- Adjustable wrench (10 in. and 12 in.)
- Socket set (3/8 in. and 1/2 in. drive) and wrenches — 3/8 in., 7/16 in., 1/2 in., and 9/16 in. sizes
- Allen wrench set (for set screws)
- Locking pliers / vise grips (2 pair)
- Tape measure (25 ft minimum)
- Ruler or caliper for wire gauge measurement
- Level (4 ft)
- Step ladder (6 ft or 8 ft as needed)
- Cordless drill/driver with socket adapters
- C-clamps or locking pliers for track clamping
- Pry bar
- Wire cutters
- Permanent marker or chalk
- Safety cable or aircraft cable for spring containment (commercial)
- File (for deburring cone or shaft)
- Spray lubricant (garage door rated)
- Rags / shop towels
Procedure — 8 Steps
Step 1
Pre-Job Assessment
A broken torsion spring still has residual energy in the remaining piece attached to the cone. Treat ALL springs as loaded until you have verified they are fully unwound. Never attempt to measure a spring by reaching between the coils of a wound spring. If one spring of a two-spring system has broken, the remaining spring is still under full tension and is extremely dangerous.
Before touching anything, assess the door system completely. Identify the spring type: standard residential torsion (single or double spring on torsion bar above the door), commercial duplex torsion (multiple springs on a shared shaft), or EZ-SET (internal torsion, wound from the side). Measure the existing spring(s) even if broken — you need three measurements: (1) overall spring length in inches (measure the coil body, not including the cones), (2) inside diameter of the spring coils (use a tape or caliper inside the coil — common residential IDs are 1-3/4 in. and 2 in.), and (3) wire size (measure 10 or 20 coils tightly packed and divide by the count to get wire diameter; compare to a wire gauge chart). Count the number of coils if the spring is intact. Record the winding direction by looking at the spring end-on: the free end of the wire points counterclockwise on a right-wound spring and clockwise on a left-wound spring (with the wire end at the top, right-wound points left, left-wound points right). Cone color is a cross-check: red cone = right wind, black cone = left wind. Standard two-spring systems use one left-wound and one right-wound spring. Calculate the inches per pound per turn (IPPT) or use a spring calculation chart to verify the replacement spring matches the door weight. Weigh the door if possible using a scale at mid-height to confirm. Verify you have the correct replacement spring(s) before beginning work.
Pro Tips
- If the spring is broken in the middle, measure both pieces and add the lengths together, accounting for the gap where the break occurred.
- Always replace springs in matched pairs on a two-spring system. Even if only one has broken, the other has the same cycle life and will fail soon.
- Take a photo of the spring setup before starting — it documents the original configuration for reference during installation.
- The DASMA color code on the cone (or paint on the spring body) indicates the wire gauge. Use this as a cross-reference, but always verify by measuring.
- For commercial doors, get the door weight from the manufacturer spec plate if available. Commercial doors are frequently too heavy to scale in the field.
Checklist
Training Videos
Disclaimer: These videos are produced by third-party YouTube channels and are not affiliated with Doorbot. Video content may not align exactly with the procedures above, may depict techniques that differ from DASMA or manufacturer recommendations, and may show tasks that are dangerous if performed without proper training and equipment. Always follow the written procedure, your company's safety policies, and applicable industry standards. Use these videos as supplementary reference only.
References & Standards
- DASMA TDS-190 — Factors Affecting Spring Cycle Life
- Spring manufacturer's rated turns chart
- Door manufacturer installation manual
- IDA / Longen Foundation — Safe Torsion Spring Practices