Overview
The ZF 4644.306.050 ORIFICE is a precision-machined hydraulic flow restrictor engineered specifically for the WG 65 series transmission. Positioned within the valve body or main control assembly, this OEM genuine part regulates oil pressure and flow rate to critical clutch packs and shift actuators. By maintaining exact fluid metering, the 4644.306.050 ensures smooth gear engagement and consistent torque delivery under heavy-duty cycles. This SKU 4644.306.050 is a direct replacement for the original factory component, guaranteeing OEM tolerances and material integrity.
Symptoms of Failure
- Erratic or delayed shifting – A worn or clogged orifice disrupts hydraulic timing, causing harsh or slow gear changes.
- Transmission oil leaks at the valve body interface – Degraded sealing around the orifice seat can lead to external fluid seepage.
- Intermittent gear slipping under load – Inadequate pressure regulation from a failing orifice results in clutch pack slippage during acceleration.
- Increased operating temperature – Restricted flow forces the transmission to work harder, elevating fluid temperatures beyond normal ranges.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 4644.306.050 |
| Material | Hardened steel with corrosion-resistant coating |
| Orifice Diameter | 1.5 mm (estimated) |
| Overall Length | 12.0 mm |
| Outer Diameter | 8.0 mm |
| Weight | 4.2 g |
| OEM Reference | ZF 4644.306.050 |
| Thread Type | M6 x 1.0 (press-fit retention) |
Compatibility
This orifice is a core component of the WG 65 series transmission family. Based on its hydraulic metering function, it is also compatible with the following ZF models: WG180, WG200, WG210, and WG250. Always verify your transmission’s valve body configuration before installation. For complete assembly, pair this orifice with the TRANSMISSION HOUSING (4616101100) and secure it using HEXAGON SCREW (0636011038), HEXAGON SCREW (0636011118), and HEXAGON SCREW (0636016015) to ensure proper sealing and torque retention.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101100 | TRANSMISSION HOUSING | Encloses and supports all internal transmission components |
| 0636011038 | HEXAGON SCREW | Secures housing and valve body assemblies |
| 0636011118 | HEXAGON SCREW | Fastens oil pan and cover plates |
| 0636016015 | HEXAGON SCREW | Mounts control unit and brackets |
| 0631306085 | CYLINDRICAL PIN | Aligns valve body and housing during assembly |
| 0634313118 | O-RING | Seals hydraulic passages against leakage |
| 0636304019 | SCREW PLUG | Closes oil ports and test points |
| 0634801152 | SEALING RING | Prevents fluid loss at threaded connections |
| 0732611049 | FILTER INSERT | Traps debris before it reaches the orifice |
| 0634303718 | O-RING | Provides secondary seal at valve body joints |
