ZF 0737.835.172 UNION SCREW for WG210 | OEM Genuine Part

Overview

The ZF 0737.835.172 UNION SCREW is a critical hydraulic sealing and connection component engineered specifically for the WG 210 series transmission. This OEM genuine part, identified by SKU 0737.835.172, functions as a high-pressure fluid coupling point within the valve body and main control assembly. It ensures a leak-free interface between the transmission housing and hydraulic lines, maintaining consistent oil pressure for clutch engagement and gear shifts. When installed alongside a TRANSMISSION HOUSING (4644101180) or a TRANSMISSION HOUSING (4644301225), this union screw provides the structural integrity required for sustained heavy-duty operation.

Symptoms of Failure

When the 0737.835.172 union screw degrades, operators typically encounter these specific failure modes:

• External hydraulic oil seepage at the union screw base – visible drips or wet spots around the screw head, often mistaken for a housing crack.
• Erratic gear engagement or delayed shifting – caused by internal pressure loss through a compromised sealing surface.
• Transmission overheating under load – insufficient fluid pressure reduces lubrication flow, increasing friction in the clutch packs.
• Whining or cavitation noise from the pump circuit – air ingestion through a loose or corroded union screw disrupts hydraulic prime.

Technical Specifications

Compatibility

This union screw is factory-specified for the ZF WG 200 Series and WG 210 Series transmissions. It directly fits models including WG180, WG200, WG210, and WG211. The part is also compatible with certain variants of the ZF Ecomat 4HP and 5HP series where the hydraulic block uses M14 ports. Always verify the thread pitch against your existing GROOVED STUD (0631311009) and the TYPE PLATE (0730365067) for exact model identification before installation.

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