ZF 0631.511.023 WOODRUFF KEY | OEM Genuine Part

Overview

The ZF 0631.511.023 WOODRUFF KEY is a precision-machined OEM genuine component designed to secure rotating elements within ZF power shift transmissions. This small yet critical fastener prevents relative motion between a shaft and its mounted hub, such as a gear or pulley, ensuring torque is transmitted without slippage. In heavy-duty construction machinery, the 0631.511.023 Woodruff Key sits within the transmission’s gear train assembly, locking components like the GEAR SHAFT to its corresponding drive element. Its half-moon profile provides a positive lock while allowing for slight axial misalignment, making it indispensable for maintaining driveline integrity under high cyclic loads.

Symptoms of Failure

• Intermittent gear slipping under load: When the Woodruff Key shears or wears, the gear loses its positive engagement with the shaft, causing sudden loss of power transfer during excavation or grading operations.
• Abnormal metallic rattling from the transmission housing: A loose key allows the gear to shift axially, producing a distinct clattering noise that worsens as the HOUSING vibrates against the damaged keyway.
• Difficulty engaging specific forward or reverse gears: Worn key profiles prevent the gear from seating correctly on the shaft, leading to hard shifting or incomplete engagement in ZF WG-series transmissions.
• Visible metal debris in transmission oil: Sheared key fragments contaminate the hydraulic fluid, accelerating wear on the PLANET CARRIER and other rotating assemblies.

Technical Specifications

Compatibility

This Woodruff Key is engineered for ZF’s heavy-duty powershift transmission families commonly used in construction machinery. It is a direct fit for the WG180, WG200, and WG250 series transmissions. Additionally, it is compatible with select WG160 and WG310 models where the keyway dimensions match. The 0631.511.023 is often replaced alongside the BASIC PARTS kit during a full transmission overhaul to ensure all locking elements are renewed simultaneously.

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