ZF 4108.303.384 SUN GEAR for WG100/WG130/WG131 | OEM Genuine Part

Overview

The ZF 4108.303.384 SUN GEAR is a critical planetary component within the WG100, WG130, and WG131 transmission assemblies. This OEM genuine part serves as the central driving gear in the planetary gear set, transferring torque from the input shaft to the planetary pinions. As the primary load-bearing element in the gear train, the sun gear must maintain precise tooth geometry and surface hardness to ensure smooth power flow. The SKU 4108.303.384 is manufactured to ZF’s original specifications, guaranteeing exact fitment and metallurgical integrity for demanding industrial applications.

Symptoms of Failure

When the ZF 4108.303.384 sun gear begins to fail, operators typically notice intermittent gear slipping under load, particularly during acceleration or hill climbs. A second common symptom is whining or grinding noises from the transmission housing, which intensifies as the gear teeth develop pitting or spalling. Third, metallic debris in the transmission oil filter indicates advanced wear of the sun gear’s hardened tooth flanks. Finally, erratic shifting patterns may occur as the worn gear disrupts the planetary gear set’s rotational balance, causing delayed engagement or harsh shifts.

Technical Specifications

Compatibility

This sun gear is engineered for the ZF WG100, WG130, and WG131 series transmissions. It also fits select variants of the WG180 and WG200 models when used with the correct 4108101108: HOUSING assembly. The gear interfaces directly with the 4108301436: INPUT SHAFT and requires a new 4108306172: GASKET during installation to prevent oil seepage. Always verify the transmission serial number against the 0730365280: TYPE PLATE to confirm compatibility before ordering.

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