ZF 0731.611.025 ORIFICE for WG200/WG201/WG250 | OEM Genuine Part

Overview

The ZF 0731.611.025 ORIFICE is a precision-machined hydraulic flow restrictor engineered for the lubrication and cooling circuits within the WG200, WG201, and WG250 series transmissions. This OEM genuine part regulates oil pressure and volume to critical bearing surfaces and clutch packs, ensuring consistent thermal management and smooth gear engagement. Installed within the main valve body or housing gallery, the SKU 0731.611.025 works in concert with the TRANSMISSION HOUSING (4644101175) and the TRANSMISSION HOUSING (4644301221) to maintain proper hydraulic balance. Without this calibrated orifice, the entire lubrication network loses its metering capability, leading to premature component wear.

Symptoms of Failure

• Erratic shift timing or gear slipping: A clogged or eroded orifice disrupts hydraulic pressure to clutch packs, causing delayed engagement or unexpected gear hunting during acceleration.
• Elevated transmission oil temperature: When the orifice fails to meter flow, insufficient cooling oil reaches heat exchangers, leading to chronic overheating and degraded fluid viscosity.
• Audible whining or cavitation noise: A restricted orifice creates turbulence and air entrainment in the oil circuit, producing a high-pitched whine from the pump or valve body area.
• Oil leaks around housing seals: Backpressure from a blocked orifice can force oil past gaskets and the GROOVED STUD (0631311009) interfaces, resulting in visible drips on the bell housing.

Technical Specifications

Compatibility

This orifice is directly compatible with ZF WG180, WG200, WG201, and WG250 series transmissions used in off-highway trucks, wheel loaders, and agricultural machinery. It also fits select ZF 4WG and 6WG variants where the hydraulic control system uses a threaded metering port. Always verify the TYPE PLATE (0730365067) on your transmission housing to confirm the exact series before installation.

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