ZF 4699.804.134 GK25 | OEM Genuine Part

Overview

The ZF 4699.804.134 GK25 is a precision-engineered gear set assembly designed for the power take-off (PTO) section of heavy-duty ZF transmissions used in construction machinery. This OEM genuine part, identified by SKU 4699.804.134, serves as the primary torque transfer interface between the engine and hydraulic pumps, ensuring reliable power delivery for excavators, wheel loaders, and crawlers. The GK25 assembly integrates directly into the transmission housing, where it meshes with the input shaft to drive auxiliary equipment. For optimal performance, this component is often replaced alongside the 4699004121: GK25 unit, which shares the same gear ratio profile.

Symptoms of Failure

• Intermittent gear slipping under load: When the GK25 gear teeth wear or chip, operators may notice a sudden loss of hydraulic power during heavy digging or lifting cycles, particularly in ZF WG200 transmissions.
• Metallic grinding noise from the PTO housing: Worn bearings or damaged gear surfaces produce a distinct high-pitched whine or grinding sound, especially during cold starts or when engaging the PTO clutch.
• Hydraulic system pressure drop: A failing 4699.804.134 can cause inconsistent pump output, leading to sluggish boom or bucket movements. This symptom often accompanies oil contamination from gear debris.
• Visible oil leaks near the PTO flange: Cracks in the gear housing or degraded seals allow transmission fluid to escape, creating a wet patch around the 4699101098: HOUSING assembly.

Technical Specifications

Compatibility

This GK25 gear set is primarily compatible with ZF WG180, WG200, and WG210 series transmissions found in construction machinery such as Komatsu, Caterpillar, and Volvo excavators. It also fits select ZF 4WG-200 and 6WG-200 variants used in wheel loaders. The part interfaces directly with the 4699102146: INPUT shaft assembly and the 4699103059: OUTPUT flange, making it critical for synchronized power distribution. Always verify transmission serial numbers before ordering, as minor design changes occurred after 2018 production runs.

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