ZF 8605.955.140 PISTON PUMP for WG150 | OEM Genuine Part

Overview

The ZF 8605.955.140 PISTON PUMP is a critical hydraulic component engineered specifically for the WG 150 Series transmission. This OEM genuine part generates the precise oil flow and pressure required to actuate clutch packs and maintain lubrication within the gear train. As the heart of the hydraulic control system, the pump draws fluid from the sump and delivers it through the valve body. The SKU 8605.955.140 is the direct replacement for the original factory-installed unit, ensuring exact fitment and performance. This pump mounts directly to the TRANSMISSION HOUSING (part 4642101109) and works in tandem with the TRANSMISSION HOUSING (part 4642301205) to form a sealed hydraulic circuit.

Symptoms of Failure

• Intermittent gear slipping under load: When the piston pump loses volumetric efficiency, the transmission fails to hold pressure, causing clutches to slip during acceleration or uphill driving.
• Delayed engagement or harsh shifting: A worn pump cannot build adequate standby pressure, resulting in a noticeable lag when shifting from Neutral to Drive or Reverse.
• Low hydraulic pressure warning or erratic operation: Internal wear on the piston bores or valve plate leads to pressure fluctuations, often triggering diagnostic trouble codes.
• Whining noise from the transmission sump: Cavitation or metal-to-metal contact within a failing pump produces a distinct high-pitched whine that increases with engine RPM.

Technical Specifications

Compatibility

This piston pump is primarily designed for the ZF WG 150 Series transmission. It is also compatible with the WG 180 and WG 200 models that share the same hydraulic pump mounting interface and drive gear configuration. The pump interfaces directly with the TYPE PLATE (part 0730365125) for identification and is secured using the GROOVED STUD (part 0631311009). Always verify your transmission serial number against the OEM parts list before ordering.

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