Torsion Spring Conversion from Extension System

Why this matters

Extension springs stretch along the horizontal track on each side of the door and store energy in the same way as a screen door spring, just larger. When an extension spring fails without a containment cable, the broken spring becomes a projectile. Severe head, face, and chest injuries from broken extension springs are documented in CPSC injury data going back decades. DASMA standards and most current building codes require safety cables through every extension spring. Older doors in service may have neither cables nor torsion conversion. When a customer calls for spring replacement on an extension system, the right decision is often conversion to torsion rather than like for like replacement. This document covers the conversion safety case, the decision criteria, and the install path.

Why torsion is the safer system

Torsion springs mount on a shaft above the door opening, wound to deliver lift through a drum and cable on each side. Energy is stored in the wound spring tube; if the spring breaks, the failure is contained within the spring assembly itself and the door drops slowly through the cables. The catastrophic projectile failure mode of extension is not present.

Other advantages:

• Smoother operation, less binding
• Higher cycle life (typical torsion at 10,000 cycle rating vs typical extension at 7,000 to 10,000)
• Better counterbalance through the full door travel
• Quieter
• Fewer parts overhead at the rear horizontal track

Disadvantages:

• Higher install cost (one time)
• Requires header space above the door opening (typically 12 inches minimum for standard low headroom; 4 to 6 inches with low headroom kits and double track)
• Installer must be trained on torsion safety (winding is the kill step, not extension hangers)

When conversion is the right call

Recommend conversion to torsion when any of these apply:

• Existing extension system has no safety cables through the springs
• Existing extension springs are at end of cycle life (5+ years on a 7,000 cycle pair, daily use)
• Customer is upgrading opener for use with smart home and would benefit from quieter operation
• Existing extension springs have visible damage (corrosion, hook deformation, prior repair welds)
• Door is over 7 ft tall or over 9 ft wide (heavier doors benefit from torsion lift consistency)
• Customer is hard of hearing or has small children and a quiet, contained failure mode is valued

Recommend like for like extension replacement only when:

• Headroom is genuinely insufficient for torsion (under 4 inches above the door)
• Customer is budget constrained and accepts the safety case in writing
• Door is light, narrow, and low cycle use (detached small garage with infrequent use)

Headroom and torsion assembly clearance

Standard torsion mount requires:

• 12 inches minimum from top of door opening to ceiling for standard mount
• 6 to 12 inches with low headroom conversion (springs mounted toward the rear over the horizontal track via low headroom brackets and double track)
• 4 to 6 inches with EZ-Set or similar reduced clearance kits, with limitations on door weight

Measure before quoting. Customers do not understand headroom; they will measure to a ceiling joist and not to the actual obstruction.

Pre conversion measurement

Before ordering the torsion package:

1. Door width. Measure rough opening width to the nearest 1/8 inch.
2. Door height. Measure rough opening height to the nearest 1/8 inch.
3. Door weight. Weigh on a bathroom scale at the bottom of the door with the door fully closed and existing extension disconnected (springs slack). For estimation, use door panel maker spec sheets; for accuracy, weigh.
4. Headroom. Measure from top of opening to lowest ceiling obstruction.
5. Backroom. Measure from inside face of door to rear wall.
6. Drum size. Standard 4 inch drum for doors up to 8 ft tall, larger drums for taller doors.
7. Cycle life. 10,000 cycle (standard), 25,000, 50,000, or 100,000. Match to customer use.

Order the torsion package matched to door weight, height, and cycle life. Do not guess; spring wind specifications come from manufacturer charts (IDC, Wayne Dalton, Clopay, DASMA reference tables).

Conversion procedure overview

This is a safety summary, not a full step by step install. Full conversion requires manufacturer install documentation and torsion specific tools (winding bars, sockets, ratchet, cable clamps).

1. Open the door fully and clamp it open with locking pliers on the track below the bottom roller on each side. The door must be fully unloaded before any spring work.
2. Remove the extension springs. With the door open and clamped, the extension springs are slack. Disconnect from the hangers and pulleys. Remove and dispose.
3. Remove the existing safety cables, pulleys, and hangers that supported the extension system.
4. Install the torsion tube assembly per the package instructions: center bearing plate first, end bearing plates with anchors at each end, torsion tube through the bearings.
5. Install drums on each end of the tube, set screws aligned per manufacturer.
6. Install cables from the bottom bracket on each side up to the drum, threaded through the cable groove.
7. Install torsion springs on the tube, secured at the stationary cone in the center.
8. Wind the springs to the spring chart turn count using winding bars rated for the bar diameter. NEVER use rebar or improvised winding tools.
9. Set the drum cable tension equal on each side by spinning the drum to remove slack and tightening the drum set screws.
10. Test door balance with the opener disconnected: door should stay put at any height between full open and full close, with at most slow drift.
11. Reconnect opener, test full cycle, test force and travel limits, test photo eye reversal.

Tools required

• Winding bars rated for the spring cone bar opening (typically 1/2 inch for residential)
• Socket and ratchet for end bearing and bracket bolts
• Vice grips for door clamping
• Drill driver for lag screws into header
• Tape measure
• Level
• Safety glasses, gloves, hard hat

After conversion

• Mark the spring wind count on the spring with a permanent marker so future service knows the start point
• Mark the install date on the spring
• Replace the old door balance label with a new one indicating torsion conversion and the install date
• Update the customer file with the new system, cycle rating, and recommended service interval (annual balance check)
• Cycle the door 5 to 10 times before leaving to confirm smooth operation

References

• DASMA Technical Data Sheets on torsion spring sizing and replacement
• ANSI / DASMA 102 Specifications for Sectional Doors
• ANSI / DASMA 105 Test Methods for Sectional Doors (durability)
• Spring chart references from the spring manufacturer (IDC, Service Spring, Trump Mfg)
• CPSC garage door injury data on extension spring projectile failures