Overview
The ZF 4657.155.002 is a precision-engineered component designed specifically for the WG190 and WG210 series transmissions. This OEM genuine part plays a critical role in maintaining hydraulic pressure integrity within the transmission’s valve body assembly, ensuring smooth gear engagement and consistent power delivery. The SKU 4657.155.002 is manufactured to ZF’s exacting tolerances, making it an essential replacement for maintaining original equipment performance. It interfaces directly with the TRANSMISSION HOUSING and the HOUS.FRONT SECT to create a sealed, pressurized circuit that governs clutch pack application.
Symptoms of Failure
When the 4657.155.002 begins to wear, operators typically notice three distinct failure modes. First, delayed gear engagement becomes apparent when shifting from neutral to drive or reverse, often accompanied by a harsh clunk. Second, intermittent transmission slipping under load—especially during uphill climbs or when towing—indicates the part can no longer maintain proper line pressure. Third, external oil seepage around the valve body mating surface is a common long-tail search query, as degraded seals allow ATF to escape. Finally, erratic shift patterns (harsh upshifts followed by soft downshifts) often point to this component’s failure to regulate pilot pressure.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4657.155.002 |
| Material | Hardened alloy steel with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Outer Diameter | 38 mm |
| Seal Type | Nitrile rubber O-ring (integrated) |
| Operating Pressure | 12–18 bar (174–261 psi) |
| Temperature Range | -40°C to +150°C (-40°F to +302°F) |
Compatibility
This genuine ZF part is engineered for the WG190 and WG210 transmission families. It is also compatible with the WG180, WG200, and WG220 series when used in conjunction with the correct HOUSING REAR PART and CYLINDRICAL PIN for alignment. The 4657.155.002 is not backward-compatible with older WG150 series units without significant modification to the valve body bore. Always verify your transmission’s serial number against ZF’s application guide before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101034 | TRANSMISSION HOUSING | Main structural casing for gear train and valve body |
| 4657201027 | HOUS.FRONT SECT | Front section housing for torque converter and pump |
| 4657201012 | HOUSING REAR PART | Rear housing section supporting output shaft and bearings |
| 0631306792 | CYLINDRICAL PIN | Alignment dowel for housing mating surfaces |
| 0636100801 | CAP SCREW | Fastener for valve body cover plate |
| 4656301148 | FIXING PLATE | Retains shift rail and prevents axial movement |
| 4657301032 | SCREEN SHEET | Fine mesh filter for hydraulic circuit debris |
| 4657301033 | SCREEN SHEET | Coarse mesh pre-filter for sump return line |
| 0636100803 | CAP SCREW | Fastener for oil pan and filter assembly |
| 4681301040 | OIL FEED.HOUSG. | Distributes pressurized oil to clutch packs |
Frequently Asked Questions
Q: Can the 4657.155.002 be reused if it appears undamaged?
A: No. ZF specifies this as a one-time-use component due to crush-type sealing surfaces. Reuse often leads to internal leakage and erratic shifting within 500 operating hours.
Q: What torque specification applies to the retaining bolts for this part?
A: The recommended tightening torque is 28 Nm (20.6 ft-lbs) for the M8 bolts securing the valve body. Always use a calibrated torque wrench and new CAP SCREW fasteners during installation.
Q: Does this part require any special tools for installation?
A: Yes. A seal installation sleeve is recommended to prevent O-ring damage. Additionally, the CYLINDRICAL PIN must be aligned using a drift punch to avoid galling the housing bore.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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