ZF 4143.303.026 HELICAL GEAR for WG100/WG130/WG131 | OEM Genuine Part

Overview

The ZF 4143.303.026 HELICAL GEAR is a precision-machined component engineered for the auxiliary drive and power take-off (PTO) circuits within ZF WG100, WG130, and WG131 transmission assemblies. This OEM genuine gear transfers rotational torque from the input shaft to the oil pump and hydraulic control system, ensuring consistent lubrication and clutch engagement pressure. The SKU 4143.303.026 is manufactured to exacting ZF tolerances, featuring a hardened helical tooth profile that minimizes noise and vibration during high-load operation. When installed alongside the 4143101009: HOUSING and 4143301025: HOUSING, this gear forms the core of the transmission’s hydraulic drive train.

Symptoms of Failure

• Erratic gear engagement and slipping under load: Worn helical teeth cause intermittent power transfer, leading to delayed or harsh shifts, especially during uphill operation.
• High-pitched whining or grinding noise from the transmission housing: Damaged gear flanks produce audible metallic sounds that intensify with engine RPM, often misdiagnosed as bearing failure.
• Low hydraulic pressure and oil starvation: A stripped or chipped gear reduces pump output, triggering warning lights and sluggish clutch response.
• Metal debris in transmission fluid: Flaking or pitting on the gear surface contaminates the oil, accelerating wear on the 0634313603: O-RING and adjacent seals.

Technical Specifications

Compatibility

This helical gear is a direct replacement for ZF transmissions in the WG100, WG130, and WG131 series. It also fits select variants of the WG180, WG200, and HL 100/HL 270 series where the auxiliary drive configuration matches the 24-tooth helical profile. Always verify the spline count and bore diameter against your existing gear before installation. The gear mates directly with the 4475280018: SCREW PLUG and requires a fresh 0634313603: O-RING during reassembly to prevent fluid bypass.

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