ZF 4699.803.027 GK20 | OEM Genuine Part

Overview

The ZF 4699.803.027 GK20 is a precision-engineered genuine OEM part designed for the clutch pack assembly within ZF heavy-duty powershift transmissions. This component, identified by SKU 4699.803.027, functions as a critical piston or actuation element that applies hydraulic pressure to engage specific gear sets. Located inside the main transmission housing, it directly controls torque flow in construction machinery such as wheel loaders and graders. When this part degrades, the entire shift sequence becomes compromised, leading to operational delays and costly downtime.

Symptoms of Failure

• Delayed or harsh gear engagement — If the 4699.803.027 piston seizes or leaks internally, you will notice a pronounced lag when shifting from neutral to forward or reverse, often accompanied by a jarring clunk.
• Intermittent clutch slip under load — Worn sealing surfaces cause pressure loss, resulting in the transmission slipping when the machine is under heavy digging or pushing loads.
• Contaminated transmission fluid — Debris from a failing piston can circulate through the system, accelerating wear on the HOUSING (4699101046) and the HOUSING (4699301109).
• Erratic shift patterns — The transmission may unexpectedly drop out of gear or fail to hold a selected range due to inconsistent hydraulic pressure from the worn GK20 assembly.

Technical Specifications

Compatibility

This genuine ZF part is engineered for the GK20 clutch pack family, commonly found in the following ZF transmission models used in construction machinery: WG180, WG200, WG210, and WG250 series. It is also compatible with select ErgoPower and Ecolife variants that utilize the same piston geometry. Always verify your transmission serial number before ordering.

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