ZF 4108.202.051 SUN GEAR SHAFT for WG100/WG130/WG131 | OEM Genuine Part

Overview

The ZF 4108.202.051 SUN GEAR SHAFT is a critical internal component designed for the WG100, WG130, and WG131 transmission series. This OEM genuine part serves as the central torque-transfer element within the planetary gear set, directly meshing with the planet gears to convert hydraulic motor power into mechanical output. As a precision-machined shaft, it sits at the core of the gear train, ensuring smooth power flow from the torque converter to the output shaft. The SKU 4108.202.051 is factory-specification matched to maintain original gear ratios and load capacity. When replacing this shaft, it is essential to inspect the surrounding TRANSMISSION HOUSING for wear, as housing deformation can accelerate sun gear failure.

Symptoms of Failure

• Gear slipping under load: A worn sun gear shaft loses tooth engagement, causing the transmission to slip during acceleration or hill climbs.
• Metallic grinding noise: Pitting or spalling on the shaft teeth produces a distinct grinding sound, especially in lower gears.
• Oil contamination with metal debris: As the shaft degrades, fine metallic particles enter the hydraulic circuit, often visible when checking the OIL LEVEL GAGE.
• Erratic shifting or delayed engagement: Excessive axial play in the sun gear shaft disrupts clutch pack timing, leading to harsh or delayed shifts.

Technical Specifications

Compatibility

This sun gear shaft is engineered for the ZF WG series of powershift transmissions. It is directly compatible with the following models: WG100, WG130, and WG131. These transmissions are commonly found in agricultural tractors, construction loaders, and industrial material handlers. For proper sealing during installation, always replace the SCREW PLUG and the SCREW PLUG at the housing ports to prevent oil leaks. The shaft also interfaces with the PLANET CARRIER and PLANETARY GEAR assemblies; verify these components for wear during service.

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