ZF 4657.026.022 for WG190 | OEM Genuine Part

Overview

This genuine OEM ZF part, the ZF 4657.026.022 (SKU: 4657.026.022), is a critical internal component engineered specifically for the WG 190 Series transmission. It functions as a precision-machined guide or spacer element within the clutch pack assembly, ensuring correct axial clearance and alignment of rotating components. Without this part, the transmission cannot maintain proper hydraulic pressure distribution, leading to inefficient power transfer. The 4657.026.022 is often replaced in conjunction with the TRANSMISSION HOUSING (4657101033) and the HOUS.FRONT SECT (4657201027) during a major overhaul to restore factory tolerances.

Symptoms of Failure

When the ZF 4657.026.022 wears beyond specification, operators will notice distinct performance degradation. Look for these specific failure symptoms:

• Delayed gear engagement when shifting from Neutral to Drive: A worn part allows excessive clutch pack clearance, causing a noticeable lag before the transmission takes power.
• Intermittent oil pressure fluctuations on the gauge: Internal leakage past this component disrupts the hydraulic circuit, leading to erratic pressure readings during operation.
• Metallic debris in the transmission oil filter: As the part wears, fine metal particles shed into the lubrication system, often found during routine oil sampling.
• Audible whining or grinding noise in neutral: Incorrect axial positioning of the gear train creates friction, generating a high-pitched sound that increases with engine RPM.

Technical Specifications

Compatibility

This genuine 4657.026.022 part is primarily designed for the ZF WG 190 Series transmission family. Based on its physical dimensions and application, it is also compatible with the following ZF models that share the same clutch pack architecture: WG180, WG200, and WG210. Always verify the part number against your transmission’s serial plate. During installation, ensure the HOUSING REAR PART (4657201012) is free of scoring, and replace the CYLINDRICAL PIN (0631306792) if it shows any wear.

Related Components

Frequently Asked Questions

Q: Can I install the 4657.026.022 without replacing the TRANSMISSION HOUSING?
A: Yes, you can install this part independently if the housing is in good condition. However, we recommend inspecting the TRANSMISSION HOUSING (4657101033) for wear at the mating surface, as a damaged housing will accelerate wear on the new component.

Q: How do I know if my WG190 transmission needs this specific part?
A: If you are experiencing the failure symptoms listed above—particularly delayed engagement and metallic debris—this part is likely worn. Always cross-reference your transmission serial number with the OEM parts catalog to confirm the 4657.026.022 is the correct revision for your unit.

Q: Is the 4657.026.022 interchangeable with any aftermarket parts?
A: This is a genuine OEM ZF part. While aftermarket alternatives may exist, only the OEM 4657.026.022 guarantees the exact material hardness and dimensional tolerances required for the WG190 clutch pack. Using non-OEM parts can void transmission warranties.