ZF 0631.501.312 FITTED KEY | OEM Genuine Part

Overview

The ZF 0631.501.312 FITTED KEY is a precision-machined OEM genuine part designed to secure rotating components within the transmission assembly. This fitted key, identified by SKU 0631.501.312, sits between the shaft and the hub of a gear or coupling, transmitting torque while preventing rotational slippage. It is a critical element in the drivetrain of heavy construction machinery, ensuring that power is transferred efficiently from the transmission to the final drive. The part is often installed inside the main housing, working in conjunction with components like the 4699101043 HOUSING and the 4699301106 HOUSING to maintain structural integrity under high load conditions.

Symptoms of Failure

When the ZF 0631.501.312 FITTED KEY wears out, operators may notice distinct performance issues. Common failure symptoms include:

• Transmission gear slipping under load – The key loses its grip, causing the gear to momentarily disengage from the shaft during heavy operation.
• Unusual knocking or clunking noises – A worn fitted key allows for excessive play between components, producing audible metallic impacts.
• Vibration in the driveline – As the key fails to maintain alignment, rotational imbalance leads to noticeable shaking.
• Oil contamination from metal debris – Abrasion of the key generates fine metallic particles that circulate through the transmission fluid.

Technical Specifications

Compatibility

This fitted key is engineered for use in ZF heavy-duty transmissions commonly found in construction machinery. Based on its design and application, it is compatible with the following ZF transmission models: WG180, WG200, WG210, and WG310. These models are widely used in wheel loaders, graders, and dump trucks. The key is often replaced alongside the 4699301015 HOUSING COVER and the 4699301085 COVER during a full transmission overhaul to ensure all mating surfaces are properly sealed and aligned.

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