Overview
This OEM genuine ZF 4656.006.304 component is a critical internal actuation and sealing element specifically engineered for the WG 115 Series transmission. Positioned within the valve body assembly, this part regulates hydraulic pressure flow to the clutch packs, ensuring precise gear engagement and smooth power delivery. The SKU 4656.006.304 is manufactured to ZF’s original tolerances, guaranteeing a direct fit and restoring factory performance in heavy-duty commercial vehicle transmissions. When replacing this unit, it is common practice to inspect the adjacent TRANSMISSION HOUSING for cracks or warping, as structural integrity is vital for maintaining correct alignment.
Symptoms of Failure
- Delayed or harsh shifting: A worn 4656.006.304 causes erratic hydraulic pressure, leading to “ZF transmission shifting hard” or “delayed engagement when accelerating.”
- Internal transmission fluid leaks: Degraded seals on this part result in “ZF WG115 oil leak from bell housing” or low fluid levels without external drips.
- Gear slipping under load: As the component loses its ability to hold pressure, operators experience “transmission slipping in 3rd gear” or “loss of power on inclines.”
- Erratic neutral-to-drive engagement: A failing unit produces “clunking noise when shifting from neutral to drive” due to unregulated clutch application.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4656.006.304 |
| Material | Hardened alloy steel with nitrile sealing elements |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Width | 38 mm |
| Height | 28 mm |
| Operating Pressure | 12-18 bar |
| OEM Reference | ZF 4656.006.304 (Genuine) |
Compatibility
This genuine ZF 4656.006.304 is primarily designed for the WG 115 Series transmission, commonly found in municipal buses, fire trucks, and medium-duty construction vehicles. It is also compatible with the WG 180 and WG 200 series transmissions that share the same valve body architecture. For proper installation, ensure the HOUS.FRONT SECT and HOUSING REAR PART are free of debris, and verify that the HOUSING REAR SECTION mating surfaces are flat to prevent fluid bypass.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101075 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4656201085 | HOUS.FRONT SECT | Front section housing the torque converter |
| 4656201094 | HOUSING REAR PART | Rear casing for output shaft support |
| 4656298060 | HOUSING REAR SECTION | End cap with bearing journal |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 4656301148 | FIXING PLATE | Retains valve body components |
| 0636100817 | CAP SCREW | M10 fastener for housing bolts |
| 4656301016 | SCREEN SHEET | Fine mesh filter for oil circuit |
| 4656301017 | SCREEN SHEET | Coarse mesh pre-filter |
| 0636100803 | CAP SCREW | M8 fastener for valve body |
Frequently Asked Questions
Q: Can I install the 4656.006.304 without replacing the housing gaskets?
A: It is strongly recommended to replace all sealing surfaces, including those on the TRANSMISSION HOUSING, when installing this part. Old gaskets can cause intermittent pressure loss and repeat failure.
Q: How do I know if my WG115 needs this specific part versus a full valve body?
A: If you have isolated “ZF transmission slipping in reverse” or “hard 2-3 upshift,” the 4656.006.304 is likely the culprit. A full valve body replacement is only necessary if multiple solenoids or bores are scored.
Q: What torque specification should I use for the cap screws securing this component?
A: Use 22 Nm (16 ft-lbs) for the CAP SCREW (M8) and 45 Nm (33 ft-lbs) for the CAP SCREW (M10) to avoid warping the HOUSING REAR PART.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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