Overview
The ZF 4657.025.114 is a precision-engineered internal component specifically designed for the WG 190 Series transmission. This OEM genuine part plays a critical role in managing hydraulic pressure distribution within the valve body assembly, directly influencing shift quality and clutch engagement timing. As a flow-control element, it ensures consistent oil delivery to the rotating clutches, preventing pressure drops during high-torque operations. The SKU 4657.025.114 is manufactured to ZF’s original tolerances, guaranteeing a direct fit without modification. When installed alongside the TRANSMISSION HOUSING, this part forms a sealed hydraulic circuit essential for smooth power transfer in heavy-duty applications.
Symptoms of Failure
- Delayed or harsh gear engagement: A worn 4657.025.114 causes erratic hydraulic pressure, leading to noticeable lag when shifting from Neutral to Drive or Reverse.
- Intermittent transmission slipping under load: As the part loses its sealing integrity, internal leakage occurs, resulting in momentary power loss during uphill climbs or towing.
- Visible oil seepage around the valve body area: Cracks or deformation in the component allow ATF to escape, leaving wet spots on the transmission pan or bell housing.
- Erratic shift patterns at low speeds: Worn internal bores cause pressure fluctuations, making the transmission hunt between gears in stop-and-go traffic.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4657.025.114 |
| Material | Hardened alloy steel with anti-corrosion coating |
| Weight | 0.42 kg (0.93 lbs) |
| Length | 68.5 mm |
| Outer Diameter | 32.0 mm |
| OEM Reference | ZF 4657.025.114 (Genuine) |
| Seal Type | Integrated PTFE lip seal |
Compatibility
This component is engineered for the ZF WG 190 Series, but its hydraulic function makes it suitable for several related models. It is directly compatible with the WG180, WG190, and WG200 transmissions found in municipal trucks, fire apparatus, and construction loaders. The part also fits select variants of the WG150 and WG210 series when used with the correct HOUS.FRONT SECT and HOUSING REAR PART. For applications requiring a complete rear seal assembly, pairing this part with the HOUSING REAR SECTION ensures optimal pressure retention.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101082 | TRANSMISSION HOUSING | Main structural casing for gear and shaft assembly |
| 4657201166 | HOUS.FRONT SECT | Front section housing for pump and converter |
| 4657201170 | HOUSING REAR PART | Rear housing section supporting output shaft |
| 4657298102 | HOUSING REAR SECTION | Complete rear housing assembly with bearing seats |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 0636100801 | CAP SCREW | M10 bolt for securing valve body covers |
| 4656301148 | FIXING PLATE | Retaining plate for clutch piston assembly |
| 4657301032 | SCREEN SHEET | Fine mesh filter for oil pump intake |
| 4657301033 | SCREEN SHEET | Coarse mesh pre-filter for valve body |
| 0636100803 | CAP SCREW | M8 bolt for transmission pan attachment |
Frequently Asked Questions
Q: Can the 4657.025.114 be reused after a transmission rebuild?
A: No. This is a wear-critical component with integrated seals that deform during use. ZF recommends mandatory replacement with a new OEM part during any valve body overhaul to prevent premature failure.
Q: Does this part require special tools for installation?
A: Yes. A calibrated torque wrench and a seal installation sleeve are necessary to avoid damaging the PTFE lip seal. Overtightening can distort the bore and cause internal leakage.
Q: How does this part interact with the HOUSING REAR SECTION?
A: The 4657.025.114 mounts directly into the valve body cavity of the HOUSING REAR SECTION, where it regulates oil flow to the rear clutch pack. Any mismatch in housing bore tolerance will cause pressure loss.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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