ZF 4407.301.139 WASHER | OEM Genuine Part

Overview

The ZF 4407.301.139 WASHER is a precision-engineered OEM genuine component designed to function as a critical sealing and load-distribution interface within heavy-duty construction machinery transmissions. This hardened steel washer sits between the transmission housing and hydraulic control assemblies, preventing fluid bypass and maintaining correct axial clearances. The SKU 4407.301.139 is often replaced during major transmission overhauls when technicians disassemble the valve body or clutch pack sections. When installed alongside the 4143101009 HOUSING and 4143301025 HOUSING, this washer ensures proper torque retention and eliminates metal-on-metal fretting that can lead to catastrophic housing cracks.

Symptoms of Failure

• Transmission fluid seepage at housing joints: A worn or crushed 4407.301.139 washer allows pressurized oil to escape between mating surfaces, leaving visible wet spots around the bell housing.
• Intermittent gear slipping under load: When this washer loses its original thickness, clutch pack clearances increase, causing delayed engagement and power loss during excavation or grading operations.
• Abnormal metallic rattling from the transmission sump: A fractured washer can shed small steel fragments that circulate through the hydraulic system, damaging the 0634313603 O-RING and valve spools.
• Torque converter shudder during cold starts: Insufficient washer height alters the pump-to-housing alignment, creating vibration that accelerates wear on the 4475280018 SCREW PLUG threads.

Technical Specifications

Compatibility

This washer is a standard fitment across multiple ZF power shift transmission families used in construction machinery. It is commonly found in the WG180, WG200, and WG210 series, where it secures the clutch piston return spring assembly. The 4407.301.139 also appears in the 4WG-200 and 5WG-300 models, typically in the torque converter housing section. For precise installation, always verify the part against the original washer stack height when replacing the 4143298457 SEAL KIT.

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