Overview
The ZF 4620.306.424 VALVE HOUSING is a precision-machined hydraulic control body that directs oil flow within the WG65 transmission series. Positioned between the main casing and the valve block assembly, this OEM genuine part regulates clutch engagement and shift timing. The SKU 4620.306.424 corresponds to the factory-spec housing used in ZF’s WG65 gearbox, ensuring exact fitment and pressure integrity. When installed alongside a 4616101065 TRANSMISSION HOUSING, it forms the core hydraulic circuit that governs torque converter lockup and gear selection.
Symptoms of Failure
- Erratic shift timing or delayed engagement — Worn valve bores cause inconsistent hydraulic pressure, leading to harsh or sluggish gear changes.
- External oil seepage from the valve body area — Cracks or warping in the housing allow transmission fluid to escape, often visible as drips near the bell housing.
- Transmission slipping under load — Internal cross-leakage between valve passages reduces clutch pack pressure, causing power loss during acceleration.
- Contaminated fluid with metallic debris — Abrasion of the housing’s internal surfaces generates fine aluminum particles that circulate through the system.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4620.306.424 |
| Material | Die-cast aluminum alloy (A380) |
| Weight | 2.85 kg (6.28 lbs) |
| Overall Dimensions | 280 mm x 180 mm x 95 mm |
| Bore Diameter (Valve Spools) | 12.7 mm ± 0.02 mm |
| OEM Reference | ZF 4620.306.424 |
| Sealing Surface Finish | Ra 0.8 µm |
| Operating Pressure Range | 8–18 bar |
Compatibility
This valve housing is engineered for the ZF WG65 series, but its hydraulic architecture also supports select models in the WG180 and WG200 families when paired with the correct valve spools. It directly replaces units in WG65 transmissions used in municipal trucks, fire apparatus, and medium-duty construction vehicles. For proper sealing, always install new 0634313118 O-RING and 0634801152 SEALING RING during reassembly. Secure the housing using 0636011038 HEXAGON SCREW (M8x25) and 0636011118 HEXAGON SCREW (M8x30) for the main flange, with 0636016015 HEXAGON SCREW (M10x40) for the accumulator bracket.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101065 | TRANSMISSION HOUSING | Main casing enclosing gear sets and valve body |
| 0636011038 | HEXAGON SCREW | M8x25 fastener for valve housing to case |
| 0636011118 | HEXAGON SCREW | M8x30 fastener for valve housing flange |
| 0636016015 | HEXAGON SCREW | M10x40 fastener for accumulator bracket |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for valve housing positioning |
| 0634313118 | O-RING | Seals valve housing to transmission case |
| 0636304019 | SCREW PLUG | Closes pressure test ports on housing |
| 0634801152 | SEALING RING | Copper washer for plug sealing |
| 0732611049 | FILTER INSERT | Inline mesh filter for valve body oil supply |
| 0634303718 | O-RING | Seals filter insert bore in housing |
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