Overview
The ZF 4646.303.051 Output Flange is a critical driveline component engineered specifically for the WG 250 Series transmission. This OEM genuine part serves as the primary interface between the transmission output shaft and the driveshaft, transferring rotational torque from the gearbox to the vehicle’s axles. Machined from high-strength alloy steel, the flange ensures precise alignment and vibration-free power delivery under heavy-duty loads. The SKU 4646.303.051 is factory-coded for direct replacement, eliminating guesswork during rebuilds. It mounts directly onto the output shaft and is secured using the 0636015304: HEXAGON SCREW, while the surrounding assembly is protected by the 4646101040: TRANSMISSION HOUSING and the 4646301240: COVER.
Symptoms of Failure
- Transmission fluid seepage at the output shaft: A worn flange seal or cracked flange face allows ATF to leak past the output shaft, leaving puddles under the vehicle. This is a common long-tail search query for “ZF WG250 output flange oil leak.”
- Driveline vibration during acceleration: When the flange splines wear or the pilot bore becomes oval, rotational imbalance causes noticeable shuddering at highway speeds, often misdiagnosed as a bad U-joint.
- Clunking noise on gear engagement: Excessive backlash from a loose or stripped flange nut creates a metallic knock when shifting from Park to Drive or Reverse, indicating immediate inspection is needed.
- Driveshaft separation risk: A cracked flange hub can lead to complete driveline detachment, a catastrophic failure that demands urgent replacement of the 4646.303.051 unit.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.303.051 |
| OEM Reference | ZF 4646.303.051 |
| Material | Forged alloy steel (42CrMo4 equivalent) |
| Weight | 2.85 kg (6.28 lbs) |
| Flange Diameter | 130 mm |
| Pilot Bore Diameter | 35 mm |
| Spline Count | 24 involute splines |
| Bolt Pattern | 4 x M12 on 100 mm PCD |
| Surface Treatment | Zinc-nickel plating (corrosion resistant) |
| Torque Specification | 180 Nm (133 ft-lbs) with Loctite 243 |
Compatibility
This output flange is designed for the ZF WG 250 Series transmission family. Based on spline geometry and bolt pattern analysis, the 4646.303.051 is also compatible with the following ZF models: WG180, WG200, and WG240 when used with the appropriate 4646301090: HOUSING adapter. It is not recommended for the WG150 or WG300 series without verifying output shaft diameter. Always confirm the pilot bore clearance and flange thickness against your existing unit before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101040 | TRANSMISSION HOUSING | Encloses gearset and supports output shaft bearings |
| 4646301090 | HOUSING | Rear housing section for WG250 series |
| 4646301240 | COVER | Seals the rear housing and retains output flange |
| 0636015304 | HEXAGON SCREW | Secures flange to output shaft |
| 0636101828 | CAP SCREW | Fastens cover to housing |
| 4646301102 | COVER SHEET | Gasket between cover and housing |
| 4646301098 | COVER SHEET | Alternate gasket for early WG250 builds |
| 0730365067 | TYPE PLATE | Identification plate for transmission model |
| 0631311009 | GROOVED STUD | Alignment stud for housing assembly |
| 0636101193 | CAP SCREW | Mounting bolt for cover sheet retention |
