ZF 4166.335.238 PUMP WHEEL for WG150/WG200 | OEM Genuine Part

Overview

The ZF 4166.335.238 PUMP WHEEL is a critical hydraulic torque converter component engineered for the WG150, WG200, and WG201 series transmissions. This OEM genuine part, identified by SKU 4166.335.238, functions as the primary impeller within the converter assembly, directing transmission fluid flow to generate torque multiplication during vehicle launch and low-speed operation. Positioned directly between the engine flexplate and the turbine assembly, this pump wheel ensures consistent hydraulic coupling and power transfer. When paired with a robust TRANSMISSION HOUSING, the assembly maintains precise alignment and fluid containment under heavy loads.

Symptoms of Failure

• Delayed or erratic gear engagement — A worn pump wheel reduces hydraulic pressure, causing hesitation when shifting from neutral to drive or reverse, a common issue in WG200 transmissions.
• Torque converter shudder at low speeds — Damaged blades create uneven fluid flow, resulting in vibration or shuddering during acceleration from a stop, often misdiagnosed as transmission slipping.
• Overheating transmission fluid — Inefficient pumping action generates excessive heat, leading to burnt-smelling fluid and potential damage to seals and the TRANSMISSION HOUSING.
• Whining or grinding noise from converter area — Worn bearings or impeller contact produce audible metallic sounds, particularly in WG150 series units under load.

Technical Specifications

Compatibility

This pump wheel is designed for ZF WG150, WG200, and WG201 series transmissions, commonly found in medium-duty trucks, buses, and construction equipment. It directly replaces OEM units in WG180 variants as well, provided the torque converter housing matches. For proper installation, verify the condition of the TYPE PLATE to confirm transmission model identification, and ensure the GROOVED STUD securing the pump wheel hub is torqued to factory specifications.

Related Components