ZF 4699.004.128 GK25 | OEM Genuine Part

Overview

The ZF 4699.004.128 GK25 is a precision-engineered OEM genuine gear kit designed for the high-torque planetary sections of ZF construction machinery transmissions. This SKU 4699.004.128 functions as the primary reduction gear set within the final drive assembly, converting rotational speed into the mechanical force required to move heavy loads. It sits directly between the 4699102146: INPUT shaft and the 4699103026: OUTPUT hub, ensuring smooth power transfer under extreme stress. As a genuine ZF component, this part guarantees exact metallurgical composition and tooth geometry to prevent premature wear in demanding excavator and wheel loader applications.

Symptoms of Failure

• Grinding noise during articulation: A distinct metallic grinding or whining sound when turning or shifting under load indicates worn gear teeth on the 4699.004.128 set.
• Intermittent drive engagement: The machine may hesitate or “skip” when power is applied, particularly in reverse, as the gear profile degrades.
• Metal particles in transmission fluid: Flakes or silver debris found during routine oil changes point directly to gear spalling or pitting on this component.
• Reduced breakout force: A noticeable loss of digging or lifting power, especially at low RPM, suggests the GK25 can no longer maintain proper gear mesh.

Technical Specifications

Compatibility

This genuine ZF GK25 gear kit is primarily compatible with the WG180 and WG200 series power shift transmissions commonly found in mid-size construction machinery. It also fits select models in the WG150 and WG250 families, particularly those used in telescopic handlers and compact crawlers. Always verify your transmission serial number against the OEM parts catalog to ensure correct fitment. The gear set works in conjunction with the 4699101098: HOUSING to maintain proper alignment and with the 4699105044: TURNTABLE BEARING for rotational stability.

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