ZF 4699.825.181 GP25 | OEM Genuine Part

Overview

The ZF 4699.825.181 GP25 is a genuine OEM gear set designed for the planetary section of heavy-duty construction machinery transmissions. This SKU 4699.825.181 functions as the primary power transfer component within the gear train, converting rotational input from the torque converter into precise output speeds for the final drive. Engineered for ZF’s WG series, this part sits directly between the input shaft and the output housing, ensuring seamless engagement under extreme load conditions. When paired with the 4699025015: GP25, it forms a matched set that maintains gear mesh integrity and reduces backlash.

Symptoms of Failure

• Intermittent gear slipping under load: When the GP25 gear teeth wear or chip, the transmission loses torque transfer capability, causing sudden RPM spikes during excavation or grading operations.
• Metallic grinding noise from the transmission housing: Worn gear surfaces produce a distinct high-pitched whine or grinding sound, particularly noticeable when shifting between forward and reverse in construction machinery.
• Oil contamination with metallic particles: As the gear set degrades, fine steel shavings appear in the transmission fluid, often detected during routine oil analysis or when draining the sump.
• Delayed engagement or harsh shifting: A failing GP25 causes erratic clutch pack engagement, leading to jerky starts or hesitation when the machine is under heavy load.

Technical Specifications

Compatibility

This genuine GP25 gear set is specifically engineered for ZF WG180, WG200, and WG250 series transmissions commonly found in wheel loaders, excavators, and telehandlers. It directly replaces the original equipment part in the planetary carrier assembly. For proper installation, ensure the 4699101156: HOUSING is inspected for wear, as a damaged housing can accelerate gear failure. The gear set interfaces with the 4699102095: INPUT shaft and the 4699103075: OUTPUT shaft, requiring precise alignment during rebuild. Always verify transmission model and serial number before ordering.

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