ZF 4699.804.110 GK25 | OEM Genuine Part

Overview

The ZF 4699.804.110 GK25 is a critical OEM genuine component engineered for the hydraulic control system within ZF heavy-duty construction machinery transmissions. This part functions as a precision-machined valve or piston assembly, regulating fluid pressure and flow to ensure smooth clutch engagement and gear shifts. The SKU 4699.804.110 is specifically designed to interface with the main transmission housing, where it works in concert with the 4699101025 HOUSING and the 4699301078 HOUSING to maintain hydraulic integrity. Without this genuine part, the transmission’s ability to modulate torque under load is severely compromised, leading to operational inefficiencies in excavators and wheel loaders.

Symptoms of Failure

When the ZF 4699.804.110 GK25 begins to wear, operators will notice distinct performance degradation. Common failure symptoms include:

• Delayed or harsh gear engagement – The valve fails to build hydraulic pressure quickly, causing a noticeable lag when shifting from neutral to drive or reverse.
• Intermittent clutch slippage under load – Worn internal seals allow fluid bypass, resulting in power loss during heavy digging or grading operations.
• Hydraulic oil contamination – Debris from a failing GK25 can migrate into the 4699301015 HOUSING COVER and 4699301085 COVER, accelerating wear on adjacent components.
• Erratic shift patterns – The transmission may hunt for gears or fail to hold a selected ratio, often accompanied by fluctuating pressure readings.

Technical Specifications

Compatibility

This genuine ZF part is primarily utilized in the GK25 valve assembly, which is found across several ZF transmission models used in construction machinery. Compatible transmissions include the WG180, WG200, and WG211 series, as well as the 4WG-200 and 6WG-250 power shift transmissions. It is also a direct replacement for units in ERGOFLEX and ECOMIX drivelines. Always verify the housing condition by inspecting the 4699101025 HOUSING and 4699301078 HOUSING during installation to prevent premature failure.

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