Overview
This OEM genuine ZF 4657.025.122 component is a critical internal structural element for the WG 190 Series transmission. Designed to maintain precise alignment within the gear train, this part ensures consistent torque transfer and reduces vibration under heavy load. The SKU 4657.025.122 interfaces directly with the main casing assembly, acting as a locating and support feature that prevents axial movement of adjacent shafts. When installed correctly, it extends the service life of the entire transmission by preserving the factory-specified clearances between rotating and stationary parts.
Symptoms of Failure
- Progressive oil seepage at the housing joint: A worn 4657.025.122 can cause misalignment, leading to gasket distortion and slow fluid loss around the TRANSMISSION HOUSING interface.
- Audible gear rattle during deceleration: When this part loses its dimensional integrity, gear lash increases, producing a distinct metallic chatter under load.
- Erratic shift timing in higher gears: Internal stress from a failing component can alter hydraulic pressure paths, causing delayed or harsh engagement in the WG190 range.
- Visible fretting wear on mounting surfaces: Inspect for polished or discolored metal where the part contacts the HOUS.FRONT SECT and HOUSING REAR PART.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4657.025.122 |
| Material | High-tensile alloy steel, nitrided |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Outer Diameter | 48 mm |
| Hardness | HRC 58-62 |
| Surface Finish | Ground and phosphate coated |
Compatibility
This genuine ZF part is engineered for the WG 190 Series transmission family. It is also compatible with the WG180, WG200, and WG210 models where the same internal locating geometry is used. The 4657.025.122 works in concert with the HOUSING REAR SECTION to maintain concentricity of the output shaft assembly. Always verify your transmission serial number against ZF application charts before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101082 | TRANSMISSION HOUSING | Main structural casing enclosing gear sets |
| 4657201166 | HOUS.FRONT SECT | Forward section supporting input shaft bearings |
| 4657201170 | HOUSING REAR PART | Rear cover providing PTO mounting points |
| 4657298102 | HOUSING REAR SECTION | Intermediate rear housing for output shaft |
| 0631306816 | CYLINDRICAL PIN | Precision dowel for alignment of housing halves |
| 0636100801 | CAP SCREW | M10 fastener securing front housing section |
| 4656301148 | FIXING PLATE | Locking plate preventing fastener loosening |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil return circuit |
| 4657301033 | SCREEN SHEET | Coarse mesh pre-filter for sump pickup |
| 0636100803 | CAP SCREW | M12 fastener for rear housing attachment |
Frequently Asked Questions
Q: Can the 4657.025.122 be reused during a rebuild?
No. This is a torque-to-yield component that deforms plastically during installation. ZF engineering guidelines mandate replacement with a new OEM part to maintain clamping force and alignment precision.
Q: What tools are required to install this part?
You will need a calibrated torque wrench, a press tool for the interference fit, and a dial indicator to verify runout after assembly. Always consult the ZF WG190 service manual for specific torque values.
Q: How does this part interact with the transmission housing?
It seats into a precision bore within the TRANSMISSION HOUSING and provides a hardened wear surface for the thrust washer. Any wear here will directly affect the HOUS.FRONT SECT alignment.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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