ZF 4699.803.026 GK20 | OEM Genuine Part

Overview

The ZF 4699.803.026 GK20 is a precision-engineered OEM genuine part designed for the clutch pack assembly within ZF heavy-duty powershift transmissions. This component plays a critical role in modulating hydraulic pressure to engage and disengage gear sets, ensuring smooth power transfer under extreme loads in construction machinery. The SKU 4699.803.026 is a direct replacement for the original factory-installed GK20, guaranteeing exact fitment and material integrity. It sits between the main housing and the piston assembly, where it must withstand high thermal stress and continuous cyclic pressure without deformation.

Symptoms of Failure

When the ZF 4699.803.026 GK20 begins to wear, operators often notice delayed gear engagement or a soft shift feel, especially when transitioning from forward to reverse under load. A second common symptom is intermittent transmission slipping during uphill operation, which can be mistaken for low fluid levels. Third, erratic clutch pressure fluctuations may appear on diagnostic tools, leading to harsh shifts or shuddering. Finally, contaminated hydraulic fluid with metallic particles is a clear indicator that the GK20 surface has degraded, requiring immediate replacement to prevent cascading damage to the 4699101046 HOUSING and adjacent components.

Technical Specifications

Compatibility

This GK20 component is primarily used in ZF WG180, WG200, and WG210 series transmissions found in wheel loaders, dozers, and graders. It also fits select variants of the ZF 4WG-200 and 6WG-200 models. Always verify the transmission serial number against the SKU 4699.803.026 to ensure correct fitment. When replacing this part, inspect the 4699301109 HOUSING for scoring and the 4699301017 BEARING COVER for wear, as these surfaces directly interface with the GK20. Additionally, the 4699301085 COVER must be torqued to factory specifications to prevent fluid bypass.

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