ZF 4699.003.020 GK20 | OEM Genuine Part

Overview

The ZF 4699.003.020 GK20 is a critical OEM genuine component engineered for the clutch pack assembly within heavy-duty ZF powershift transmissions. This part functions as a precision-machined piston or actuation element, converting hydraulic pressure into the mechanical force required to engage and disengage gear sets. Positioned directly inside the transmission housing, the GK20 works in concert with the 4699101046 HOUSING and the 4699301109 HOUSING to ensure smooth, reliable power transfer under extreme loads. The SKU 4699.003.020 is manufactured to ZF’s exacting tolerances, guaranteeing a direct fit and consistent performance in construction machinery applications.

Symptoms of Failure

When the ZF 4699.003.020 GK20 begins to wear, operators may notice specific performance degradation. Delayed gear engagement is a primary indicator, often accompanied by a hesitation when shifting from neutral into forward or reverse. Another common failure symptom is intermittent clutch slip under load, where the transmission momentarily loses power during heavy digging or climbing. Hydraulic fluid contamination from worn sealing surfaces can also occur, leading to erratic shift quality. Finally, audible grinding or whining noises from the transmission bell housing often point to this part losing its dimensional integrity.

Technical Specifications

Compatibility

This OEM genuine part is specifically designed for use in ZF WG series transmissions commonly found in construction machinery. It is a direct replacement for units in the WG180, WG200, and WG211 transmission families. The GK20 is also compatible with certain variants of the WG150 and WG250 series where the clutch pack configuration matches. For proper installation, ensure the mating surfaces on the 4699301017 BEARING COVER and the 4699301085 COVER are clean and free of debris.

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