Overview
The ZF 4644.303.095 OUTPUT FLANGE is a critical driveline component engineered specifically for the WG 181 series transmission. This OEM genuine part serves as the mechanical interface between the transmission output shaft and the propeller shaft, transferring rotational torque from the gearbox to the vehicle’s drive axle. Machined from high-strength forged steel, the flange ensures precise alignment and secure coupling under heavy-duty operating conditions. The SKU 4644.303.095 is a direct replacement unit that maintains factory tolerances, preventing vibration and driveline imbalance. When installed, it mates directly with the TRANSMISSION HOUSING (4644101217) and the TRANSMISSION HOUSING (4644301383), forming a sealed assembly that protects internal gears from contamination.
Symptoms of Failure
- Oil leakage at the output shaft seal: A worn or cracked output flange allows transmission fluid to seep past the seal, leaving puddles under the vehicle and reducing hydraulic pressure.
- Driveline vibration during acceleration: When the flange splines wear or the bolt holes elongate, rotational imbalance causes noticeable shaking through the chassis at highway speeds.
- Clunking noise when shifting gears: Excessive play between the flange and output shaft creates a metallic knock during gear engagement, indicating imminent spline failure.
- Premature bearing wear in the transmission tail housing: A loose flange transmits axial loads into the THREADED BUSH (4644301189) and the SCREW PLUG (4475280043), accelerating component degradation.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 4644.303.095 |
| Material | Forged steel, induction-hardened splines |
| Overall Diameter | 165 mm (approx.) |
| Bolt Hole Circle | 130 mm (4 holes, 14 mm diameter) |
| Spline Count | 10 internal splines (SAE standard) |
| Weight | 2.8 kg (6.2 lbs) |
| OEM Reference | ZF 4644.303.095 |
| Sealing Surface | Ground finish for lip seal compatibility |
Compatibility
This output flange is designed for the ZF WG 181 series transmission, commonly found in medium-duty trucks, buses, and construction equipment. Based on spline geometry and bolt pattern, it also fits the WG 180 and WG 200 series models. The flange is not interchangeable with the WG 150 or WG 250 series due to differing output shaft diameters. Always verify the transmission model tag before ordering. For complete assembly, pair this flange with the O-RING (0634306198) and SEALING RING (0634801098) to prevent fluid bypass.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101217 | TRANSMISSION HOUSING | Encloses gear sets and supports output shaft |
| 4644301383 | TRANSMISSION HOUSING | Alternate housing variant for WG181 |
| 4644301189 | THREADED BUSH | Provides wear surface for output shaft bearing |
| 4475280043 | SCREW PLUG | Seals oil passages in housing |
| 0634306198 | O-RING | Prevents oil leaks at flange-to-housing joint |
| 0634801098 | SEALING RING | Secondary seal for high-pressure zones |
| 0730365067 | TYPE PLATE | Identification tag for transmission model |
| 0631311009 | GROOVED STUD | Locates and secures housing components |
| 4644301161 | COVER PLATE | Protects internal components from debris |
| 0636100621 | HEXAGON SCREW | Fastens flange to output shaft |
