Overview
This OEM genuine ZF 4656.006.128 component is a critical internal actuator or shift element designed specifically for the WG 115 Series transmission. It functions as a hydraulic or mechanical control interface within the valve body or clutch pack assembly, directing oil flow to engage specific gear ratios. The SKU 4656.006.128 ensures precise modulation of line pressure, directly influencing shift quality and torque delivery. When installed alongside the TRANSMISSION HOUSING, it creates a sealed environment that prevents cross-contamination between hydraulic circuits. This part is often replaced during a full overhaul to restore factory-spec shift timing.
Symptoms of Failure
- Delayed or harsh gear engagement: A worn 4656.006.128 can cause a noticeable lag when shifting from Neutral to Drive or Reverse, often accompanied by a jarring clunk.
- Intermittent slipping under load: As the part loses its sealing capability, the transmission may momentarily lose power during uphill climbs or heavy acceleration.
- Erratic shift patterns: The transmission may hunt between gears or skip gears entirely, particularly in the 2-3 or 3-4 shift range, due to inconsistent hydraulic pressure.
- Internal fluid contamination: Debris from a failing actuator can migrate into the HOUS.FRONT SECT, causing secondary damage to valve bodies and solenoids.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4656.006.128 |
| Material | Hardened alloy steel with nitrided surface |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Outer Diameter | 38 mm |
| Seal Type | PTFE lip seal with O-ring backup |
| Operating Pressure | 8–18 bar (116–261 psi) |
| OEM Reference | ZF 4656.006.128 (Genuine) |
Compatibility
This part is engineered for the ZF WG 115 Series, but it also cross-fits select models in the WG180 and WG200 families when used with the correct HOUSING REAR PART. It is compatible with ZF 4WG115, 5WG115, and certain 6WG180 variants produced after 2008. Always verify the serial number against the HOUSING REAR SECTION to ensure correct bore alignment. This actuator is not suitable for the older WG 80 or WG 90 series without adapter plates.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 0631306816 | CYLINDRICAL PIN | Aligns and secures actuator within the valve body bore |
| 4656301148 | FIXING PLATE | Retains the actuator assembly against axial movement |
| 0636100817 | CAP SCREW | Fastens the fixing plate to the transmission housing |
| 4656301016 | SCREEN SHEET | Filters debris from hydraulic fluid entering the actuator |
| 4656301017 | SCREEN SHEET | Secondary filtration for high-pressure circuits |
| 0636100803 | CAP SCREW | Secures the screen sheet and prevents fluid bypass |
Frequently Asked Questions
Q: Can I reuse the old O-rings when installing the 4656.006.128?
A: No. Always replace all seals and O-rings when installing this actuator. Reusing old seals will cause immediate low-pressure faults and may damage the TRANSMISSION HOUSING bore surface.
Q: How do I know if my WG115 needs this specific part?
A: Check for a stamped “4656.006.128” on the side of the actuator body. If your transmission exhibits delayed reverse engagement or a 2-3 flare, this component is a likely culprit. Cross-reference with the HOUS.FRONT SECT for proper fitment.
Q: Is this part interchangeable with the 4656.006.127?
A: No. The .128 variant has a revised internal spring rate and a wider sealing land. Installing the .127 version will cause erratic shift timing and potential clutch burn. Always match the exact SKU.
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Phone: +86 158 2286 3467 |
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