ZF 4699.003.021 GK20 | OEM Genuine Part

Overview

The ZF 4699.003.021 GK20 is a precision-engineered OEM genuine part designed for critical load-bearing applications within ZF heavy-duty transmissions. This component functions as a key structural interface, ensuring proper alignment and sealing between the transmission housing and rotating assemblies. Commonly found in construction machinery such as wheel loaders, graders, and dump trucks, the SKU 4699.003.021 plays a vital role in maintaining hydraulic pressure integrity and driveline stability. When installed alongside the 4699101046 HOUSING and the 4699301109 HOUSING, it forms a sealed unit that prevents contamination ingress and lubricant loss.

Symptoms of Failure

When the ZF 4699.003.021 GK20 begins to wear, operators may notice specific performance issues. Oil seepage around the transmission bell housing is a primary indicator, often accompanied by intermittent gear engagement hesitation during cold starts. Another common symptom is abnormal metallic whining or grinding noises from the clutch pack area, which signals misalignment. Finally, erratic shift timing under load—particularly in reverse or first gear—can point to a compromised seal or bearing surface. These failure modes are frequently searched as “ZF transmission oil leak at housing” or “GK20 shift hesitation.”

Technical Specifications

Compatibility

This OEM genuine part is engineered for ZF power shift transmissions commonly deployed in construction machinery. It is directly compatible with the ZF WG180, ZF WG200, and ZF WG210 series. Additionally, it fits select ZF 4WG-200 and ZF 6WG-250 models used in articulated dump trucks and wheel loaders. For proper installation, always pair this component with the 4699301017 BEARING COVER and the 4699301085 COVER to ensure correct axial clearance and sealing.

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