ZF 4407.301.137 WASHER | OEM Genuine Part

Overview

The ZF 4407.301.137 WASHER is a precision-engineered OEM genuine component designed to maintain critical sealing pressure and axial alignment within heavy-duty construction machinery transmissions. This hardened steel washer sits between the transmission housing and hydraulic control assemblies, acting as a load-distributing interface that prevents fastener loosening under extreme vibration. The SKU 4407.301.137 is frequently specified during rebuilds of ZF power shift transmissions, where it works in conjunction with the 4143101009: HOUSING and the 4143301025: HOUSING to ensure proper component stack-up tolerances. Without this washer, hydraulic circuits cannot maintain their designed clamping force.

Symptoms of Failure

• Hydraulic oil seepage at housing joints – When the 4407.301.137 washer compresses or cracks, the 0634313603: O-RING loses its preload, causing slow drips from mating surfaces during operation.
• Intermittent gear engagement delay – A worn washer allows axial play in the valve body, leading to delayed clutch pack engagement when shifting under load.
• Abnormal transmission housing noise – Metal-to-metal contact occurs as the washer thickness diminishes, producing a distinct rattle at idle that worsens with temperature.
• Torque converter drain-back – Loss of sealing integrity at the 4475280018: SCREW PLUG interface can cause converter fluid to migrate, resulting in sluggish cold starts.

Technical Specifications

Compatibility

This washer is integral to ZF WG-series powershift transmissions commonly found in wheel loaders, dozers, and excavators. It is a direct fit for the WG180, WG200, and WG220 models, where it secures the valve body cover and clutch housing interfaces. The 4407.301.137 also appears in certain ZF 4WG-200 and ZF 6WG-250 variants used in European construction machinery. Always verify stack height when replacing this washer alongside a 4143298457: SEAL KIT to avoid over-compression of adjacent seals.

Related Components