ZF 4644.137.020 EMERGENCY STEERING PUMP for WG200 | OEM Genuine Part

Overview

The ZF 4644.137.020 EMERGENCY STEERING PUMP is a critical hydraulic component engineered specifically for the WG 200 Series powershift transmission. This OEM genuine part provides an auxiliary steering fluid supply, ensuring that directional control is maintained even if the primary pump loses pressure. Mounted directly to the transmission housing, this pump engages automatically during a pressure drop to safeguard vehicle maneuverability. The SKU 4644.137.020 is the exact replacement for factory-installed units, guaranteeing seamless integration with your existing hydraulic circuit.

Symptoms of Failure

• Steering wheel becomes heavy or unresponsive – When the emergency pump fails, operators often report a sudden increase in steering effort, particularly during low-speed maneuvers or when turning in tight spaces.
• Audible whining or grinding noise from the pump – Worn internal gears or bearing failure produce a distinct high-pitched whine or metallic grinding sound, indicating imminent pump seizure.
• Hydraulic fluid leaks near the pump mounting flange – Deteriorated seals or a cracked housing cause oil to weep from the pump base, leading to low fluid levels and eventual system cavitation.
• Intermittent loss of steering assist – A failing pump may work sporadically, causing the steering to feel normal one moment and extremely stiff the next, often accompanied by jerky wheel movements.

Technical Specifications

Compatibility

This emergency steering pump is designed for the ZF WG 200 Series transmission family. It is a direct fit for models including the WG200, WG180, and WG210. The pump interfaces with the TRANSMISSION HOUSING (4644101164) and the TRANSMISSION HOUSING (4644301371) using a precision-machined mounting flange. For proper identification, always verify the TYPE PLATE (0730365067) on your unit, and secure the assembly with the GROOVED STUD (0631311009) to prevent vibration loosening.

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