Overview
The ZF 4656.056.025 is a precision-engineered OEM genuine component specifically designed for the WG 160 Series transmission. This part functions as a critical interface element within the hydraulic control circuit, ensuring proper fluid routing and pressure regulation during gear shifts. As an OEM genuine part, the SKU 4656.056.025 guarantees exact fitment and factory-specified performance, eliminating the risk of premature wear associated with aftermarket alternatives. It sits directly within the valve body assembly, where it manages oil flow to the clutch packs and planetary gear sets.
Symptoms of Failure
When the ZF 4656.056.025 begins to wear, operators typically notice these specific failure indicators:
- Erratic shift timing or delayed engagement — The transmission hesitates before engaging gears, particularly under load, as fluid pressure drops below specification.
- Intermittent oil seepage around the valve body — Small fluid leaks appear at the mating surface between the TRANSMISSION HOUSING and the control module, indicating seal degradation.
- Harsh or clunking shifts — Sudden, jarring gear changes occur when the part fails to modulate hydraulic pressure smoothly, often accompanied by audible metallic noises.
- Transmission overheating — Restricted fluid passage causes elevated operating temperatures, triggering warning lights or thermal shutdown in severe cases.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4656.056.025 |
| Material | Hardened alloy steel with corrosion-resistant coating |
| Weight | 0.45 kg (1.0 lb) |
| Length | 85 mm |
| Width | 40 mm |
| Height | 25 mm |
| OEM Reference | ZF WG 160 Series |
| Thread Specification | M8 x 1.25 (if applicable) |
Compatibility
This genuine ZF 4656.056.025 part is primarily engineered for the WG 160 transmission series. It also demonstrates cross-compatibility with select models in the WG 180 and WG 200 families, provided the valve body configuration matches. The part interfaces directly with the HOUS.FRONT SECT and the HOUSING REAR PART (4656201035) to form a sealed hydraulic chamber. For heavy-duty applications, the HOUSING REAR PART (4472239178) is also required to complete the assembly. Always verify your transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101037 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4656201075 | HOUS.FRONT SECT | Front section housing for input shaft and bearings |
| 4656201035 | HOUSING REAR PART | Rear section enclosing output shaft assembly |
| 4472239178 | HOUSING REAR PART | Alternate rear housing for specific WG variants |
| 0631306816 | CYLINDRICAL PIN | Alignment pin for precise housing positioning |
| 4656301148 | FIXING PLATE | Secures valve body components in place |
| 0636100817 | CAP SCREW | Fastener for housing-to-transmission attachment |
| 4656301016 | SCREEN SHEET | Fine mesh filter for hydraulic fluid debris |
| 4656301017 | SCREEN SHEET | Alternative mesh filter for different fluid grades |
| 0636100803 | CAP SCREW | Shorter fastener for internal component mounting |
Frequently Asked Questions
Q: Can I use the ZF 4656.056.025 in a WG 180 transmission?
A: Yes, this part is compatible with WG 180 models that share the same valve body architecture as the WG 160. However, we recommend cross-referencing your transmission serial number with the OEM parts catalog to confirm fitment, as internal revisions may vary.
Q: What tools are required to replace this part?
A: Replacement typically requires a torque wrench, hex key set, and a seal puller. You will also need to drain the transmission fluid before accessing the valve body area where the 4656.056.025 is located.
Q: How do I know if this part is failing before complete breakdown?
A: Early warning signs include a slight delay in reverse engagement and a gradual increase in shift firmness. Monitoring transmission fluid for metallic particles during routine service can also indicate wear on this component.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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