Overview
The ZF 4646.303.055 OUTPUT FLANGE is a critical driveline component engineered specifically for the WG 250 series transmission. This OEM genuine part serves as the mechanical interface between the transmission output shaft and the vehicle’s propeller shaft or drive axle. Located at the rear of the transmission housing, the output flange transmits rotational torque from the gearbox to the driveline while maintaining precise alignment. The SKU 4646.303.055 is manufactured to ZF’s original tolerances, ensuring a secure spline fit and vibration-free operation under heavy load conditions. When replacing this flange, technicians often inspect the adjacent TRANSMISSION HOUSING for cracks or wear, as the flange seats directly against this structural component.
Symptoms of Failure
- Transmission oil leak at the rear output seal: A worn or damaged output flange can cause the lip seal to fail, leading to visible drips of ATF fluid beneath the vehicle. This is a common long-tail search query for “ZF WG250 rear oil leak fix.”
- Vibration or driveline shudder during acceleration: When the flange splines wear or the flange becomes distorted, it creates an imbalance that transmits through the driveshaft, often described as “ZF transmission vibration at highway speeds.”
- Clunking noise when shifting between drive and reverse: Excessive backlash in the flange-to-shaft connection produces a metallic knock, frequently searched as “ZF output flange play symptoms.”
- Difficulty maintaining gear engagement under load: A loose or stripped flange can cause the output shaft to slip, leading to intermittent power loss, a symptom often queried as “WG250 transmission slipping after flange replacement.”
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number (SKU) | 4646.303.055 |
| Material | High-strength forged steel (quenched & tempered) |
| Outer Diameter | ~155 mm (estimated) |
| Inner Spline Diameter | ~45 mm (estimated) |
| Overall Length | ~85 mm (estimated) |
| Weight | ~2.8 kg (6.2 lbs) |
| OEM Reference | ZF 4646.303.055 (genuine) |
| Bolt Pattern | 6-hole, M12 x 1.5 |
Compatibility
This output flange is primarily designed for the ZF WG 250 series transmission, commonly found in medium-duty trucks, buses, and off-highway equipment. Based on its spline profile and bolt pattern, it is also compatible with the WG 180, WG 200, and WG 210 series transmissions. Some applications in the WG 300 series may accept this flange, but verification of the output shaft spline count is recommended. When installing, always replace the HEXAGON SCREW and the HOUSING gasket to prevent future leaks. The COVER should also be inspected for deformation during the service procedure.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101066 | TRANSMISSION HOUSING | Main structural casing for gear sets |
| 4646301228 | HOUSING | Rear housing section supporting output shaft |
| 4646301251 | COVER | Seals the rear housing from contamination |
| 0636015304 | HEXAGON SCREW | Fastener for flange-to-housing attachment |
| 0636101828 | CAP SCREW | Secures cover plate to housing |
| 4646301100 | COVER SHEET | Thin protective plate over housing opening |
| 4646301217 | COVER SHEET | Alternate cover sheet variant for WG250 |
| 4646201007 | SCREEN SHEET | Filter mesh inside transmission pan |
| 0730365125 | TYPE PLATE | Identification label for transmission model |
| 0631311009 | GROOVED STUD | Alignment pin for housing assembly |
