ZF 4699.804.010 GK25LD | OEM Genuine Part

Overview

The ZF 4699.804.010 GK25LD is a genuine OEM shift cylinder assembly designed for heavy-duty construction machinery transmissions. This critical pneumatic actuator controls gear engagement within the transmission valve body, converting air pressure into precise mechanical movement to select forward, reverse, and neutral positions. As a direct replacement for the SKU 4699.804.010, this component ensures factory-specified shift timing and clutch pack pressure. It interfaces directly with the 4699004010: GK25LD shift mechanism and mounts securely to the 4699101002: HOUSING assembly, forming the core of the transmission control system.

Symptoms of Failure

• Delayed or harsh shifting: When the GK25LD piston seals wear, you may experience a 2-3 second lag between gear selection and engagement, or abrupt clunking sounds during shifts.
• Air pressure leaks at the actuator: Audible hissing from the transmission housing or visible oil mist around the shift cylinder indicates internal seal degradation, often accompanied by reduced clutch holding force.
• Inability to engage specific gears: A worn 4699.804.010 can cause the transmission to stick in neutral or fail to hold a selected gear under load, particularly in reverse or low range.
• Erratic neutral safety switch behavior: Intermittent starting issues or false neutral signals often trace back to a misaligned or worn shift cylinder plunger.

Technical Specifications

Compatibility

This genuine ZF part is engineered for the GK25LD shift system used in the following transmission models: WG180, WG200, WG210, and WG250 series. It is also found in certain Ecomat 4HP and 6HP variants used in wheel loaders, excavators, and dump trucks. The 4699.804.010 directly replaces the 4699102010: INPUT shaft assembly and works in tandem with the 4699103002: OUTPUT flange to complete the power flow path.

Related Components