The Detex 105433 is the OEM S&R (Service and Replacement) clock spring kit for the AO19 series low energy automatic door operator. It's a sub-component of the motor-gearbox assembly (Item 2KIT in the AO19 parts list), and it's the part that fails when a properly powered Detex AO19 starts leaving the door arm partially open, fails to return the arm to rest position after closing, or produces inconsistent closing behavior despite the motor and controller testing correctly. The clock spring is the mechanical force component inside the gearbox that works alongside the motor to control arm return. When it fatigues or breaks, the motor alone can't produce the consistent, controlled closing action the door needs.

This kit fits all five AO19 variants listed in the Detex parts catalog: AO19-1-Push, AO19-1-Pull, AO19-2-Push, AO19-2-Pull, and AO19-3.

Detex AO19 Series Automatic Door Operator Compatibility

The Detex AO19 series is a heavy-duty low energy automatic door operator designed for medium to high-traffic commercial and institutional applications including schools, hospitals, government buildings, and security-controlled entries. The AO19 series meets ANSI/BHMA A156.19 requirements for low energy power-operated doors and provides ADA-compliant automatic access for wheelchair users and people with disabilities.

AO19-1 is the single door model, available in Push and Pull configurations based on the side the operator mounts to relative to the door swing. The standard AO19-1 header measures 39.5 inches, sized to fit above a standard 36-inch commercial door opening. Extended lengths of 45.5 inches and 52 inches are also available. The AO19-1 runs on 115VAC power with a plug-in connection mounted in the header.

AO19-2 is the twin door configuration, running two motor-gearbox assemblies synchronized to operate a pair of doors simultaneously. Like the AO19-1, it's available in Push and Pull configurations.

AO19-3 is the third configuration in the series for specific mounting requirements.

The 105433 clock spring kit is listed as a replacement part for all five models in the current Detex parts catalog, making it the universal clock spring service kit across the AO19 product family.

What the Detex AO19 Clock Spring Does

The AO19 uses an electromechanical drive system. The motor-gearbox assembly handles the powered opening cycle, driving the door arm to the full open position. The clock spring is a spiral torsion spring inside the gearbox that stores mechanical energy during the opening stroke and releases it progressively during the closing cycle. It works in conjunction with the UDC 1000 Controller's close speed, latch-check, and back-check settings to produce smooth, controlled door movement from full open back to the latched position.

Without a functioning clock spring, the arm loses consistent return force. You'll typically see this as the door arm drifting rather than closing cleanly, stopping short of the latch position, or requiring more motor effort to complete the closing cycle — which accelerates wear on the gearbox. Replacing the clock spring with the 105433 kit restores the original mechanical behavior without replacing the full motor-gearbox assembly (Item 2KIT), which runs substantially higher.

The AO19 push and pull gearbox assemblies are not interchangeable, but the 105433 clock spring kit covers both.

Detex AO19 Parts: Ordering the Right Kit

The 105433 is compatible with the AO19-1-Push, AO19-1-Pull, AO19-2-Push, AO19-2-Pull, and AO19-3. Confirm your AO19 model before ordering. The full AO19 parts breakdown for each model is available as a downloadable catalog on this product page. SecurityParts carries the complete Detex AO19 parts catalog including motor-gearbox assemblies, the UDC 1000 controller, switch plate subassemblies, line filter kits, push arm assemblies, and door foot hardware for both aluminum and bronze finish operators.