Overview
This OEM genuine ZF part, the 4657.025.004, is a critical internal component designed specifically for the WG 190 series transmission. It functions as a precision-engineered sealing and alignment element within the hydraulic control circuit, ensuring consistent oil pressure delivery to the clutch packs. The 4657.025.004 sits in the valve body assembly, directly interfacing with the main control bore to regulate fluid flow during gear shifts. Without this part, the transmission cannot maintain the necessary hydraulic balance for smooth operation.
Symptoms of Failure
When the 4657.025.004 wears out, operators often report delayed engagement when shifting from neutral to drive. Another common failure sign is intermittent gear slipping under heavy load, particularly in 3rd and 4th gears. You may also notice erratic shift timing or harsh upshifts as the hydraulic pressure becomes unstable. Finally, visible oil seepage around the valve body cover can indicate that this seal has hardened or cracked.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4657.025.004 |
| Material | Hardened Steel / Nitrile Rubber Composite |
| Weight | 0.12 kg (0.26 lbs) |
| Outer Diameter | 28.5 mm |
| Inner Diameter | 12.0 mm |
| Height | 18.0 mm |
| OEM Reference | ZF 4657.025.004 |
Compatibility
This part is primarily designed for the ZF WG 190 series transmission. It is also compatible with the WG 180 and WG 200 models that share the same valve body architecture. Always verify your transmission serial number before ordering. For full assembly integrity, this component works in conjunction with the 4657101033: TRANSMISSION HOUSING, the 4657201027: HOUS.FRONT SECT, and the 4657201012: HOUSING REAR PART. A 0631306792: CYLINDRICAL PIN is also required for precise alignment during installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101033 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657201027 | HOUS.FRONT SECT | Front section housing for clutch assembly |
| 4657201012 | HOUSING REAR PART | Rear section housing for output shaft |
| 0631306792 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 0636100801 | CAP SCREW | Fastener for valve body cover |
| 4656301148 | FIXING PLATE | Retains internal shift components |
| 4657301032 | SCREEN SHEET | Fine mesh filter for hydraulic fluid |
| 4657301033 | SCREEN SHEET | Secondary filter for oil return line |
| 0636100803 | CAP SCREW | Fastener for rear housing section |
| 4681301040 | OIL FEED.HOUSG. | Distributes oil to planetary gears |
Frequently Asked Questions
Q: Can the 4657.025.004 be replaced without removing the transmission from the vehicle?
A: Yes, in most WG 190 applications, this part is accessible after removing the valve body cover. However, you must first detach the HOUSING REAR PART to access the bore.
Q: How often should this seal be inspected?
A: We recommend checking the 4657.025.004 every 500 operating hours or during any major transmission overhaul. If you notice oil leaks near the TRANSMISSION HOUSING joint, inspect this part immediately.
Q: Is the 0631306792 CYLINDRICAL PIN included with this part?
A: No, the CYLINDRICAL PIN is sold separately. It is essential for aligning the HOUS.FRONT SECT during reinstallation.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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