Overview
This OEM genuine ZF 4657.026.026 component is a critical internal sealing and alignment element specifically engineered for the WG 190 Series transmission. Positioned within the main gear train assembly, this part ensures precise hydraulic pressure distribution and prevents cross-contamination between lubrication circuits. The SKU 4657.026.026 interfaces directly with the TRANSMISSION HOUSING to maintain structural integrity under high-torque conditions. Without this part, the transmission cannot sustain proper oil flow to critical bearing surfaces, leading to accelerated wear across the entire drivetrain.
Symptoms of Failure
- Hydraulic pressure loss during gear engagement – A worn 4657.026.026 causes internal bypass, resulting in delayed or harsh shifting. This is a common “ZF WG190 slipping under load” search query.
- External oil seepage near the bell housing – Deterioration of the sealing surface leads to visible drips. Technicians often search for “ZF transmission oil leak at housing joint” when this occurs.
- Metallic debris in transmission fluid – As the part degrades, fragments contaminate the oil, which can be detected during routine “ZF WG190 filter inspection” procedures.
- Overheating in the front section – Reduced oil flow causes localized thermal stress, often flagged during “ZF transmission temperature spike diagnosis”.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4657.026.026 |
| Material | Hardened alloy steel with nitrile coating |
| Weight | 0.85 kg (1.87 lbs) |
| Outer Diameter | 68.5 mm |
| Inner Diameter | 42.0 mm |
| Height | 18.2 mm |
| OEM Reference | ZF 4657.026.026 (Genuine) |
Compatibility
This part is primarily designed for the ZF WG 190 Series but also fits the WG180, WG200, and WG210 models when used with the correct HOUS.FRONT SECT adapter. It is not compatible with the Ecomat or Ecolife series without significant modification. For proper installation, ensure the HOUSING REAR PART is free of scoring, and use a new CYLINDRICAL PIN to align the assembly during reassembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101033 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 4657201027 | HOUS.FRONT SECT | Front section housing for input shaft support |
| 4657201012 | HOUSING REAR PART | Rear housing for output bearing retention |
| 0631306792 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 0636100801 | CAP SCREW | Fastener for securing housing flanges |
| 4656301148 | FIXING PLATE | Locking plate for gear retention |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil intake |
| 4657301033 | SCREEN SHEET | Coarse mesh pre-filter for debris |
| 0636100803 | CAP SCREW | High-tensile bolt for valve body |
| 4681301040 | OIL FEED.HOUSG. | Oil distribution manifold for clutch packs |
Frequently Asked Questions
Q: Can I reuse the old CYLINDRICAL PIN when installing this part?
A: No. The CYLINDRICAL PIN should always be replaced to ensure proper alignment between the housing sections. Reusing it risks misalignment and premature failure of the 4657.026.026.
Q: How do I know if my WG190 needs this specific part?
A: If you observe oil weeping from the joint between the HOUS.FRONT SECT and the main housing, or if shift quality degrades after 200,000 km, this part is likely the culprit.
Q: Is this part interchangeable with the WG200 variant?
A: Yes, but only when used with the correct HOUSING REAR PART and updated CAP SCREWS. Always verify the housing bore diameter before installation.
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Phone: +86 158 2286 3467 |
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