ZF 4635.303.004 WASHER for WG65 | OEM Genuine Part

Overview

The ZF 4635.303.004 WASHER is an OEM genuine sealing component engineered specifically for the WG 65 series transmission. This precision-formed washer sits between the TRANSMISSION HOUSING and mating surfaces to prevent fluid migration and maintain hydraulic pressure integrity. As a critical sealing element, the SKU 4635.303.004 ensures that lubricant remains contained within the gear train, protecting internal components from contamination and wear. This washer is manufactured to ZF’s exacting tolerances, guaranteeing a perfect fit and long service life in heavy-duty industrial applications.

Symptoms of Failure

• External oil seepage around housing joints — A worn 4635.303.004 washer often manifests as visible oil drips or wet spots at the transmission housing interface, particularly after extended operation under load.
• Gradual pressure loss in hydraulic circuits — When this sealing washer degrades, operators may notice sluggish gear engagement or delayed clutch pack response due to compromised internal pressure.
• Contaminated transmission fluid — A failing washer allows external debris to bypass the seal, leading to particulate contamination that accelerates wear on bearings and planetary gears.
• Increased operating temperatures — Fluid loss from a deteriorated washer reduces lubrication volume, causing elevated heat generation within the WG65 assembly.

Technical Specifications

Compatibility

This genuine ZF washer is primarily designed for the WG 65 series transmission, but its sealing profile also suits several other ZF industrial gearbox models. Compatible transmissions include the WG180, WG200, WG250, and WG300 series, where identical housing bolt patterns and sealing grooves are employed. The 4635.303.004 is frequently used alongside HEXAGON SCREW fasteners, HEXAGON SCREW variants, and HEXAGON SCREW hardware to secure the housing assembly. Always verify your transmission model’s parts catalog before installation.

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