Overview
The ZF 4661.303.003 OUTPUT FLANGE is a critical driveline component engineered specifically for the WG 90 Series transmission family. This OEM genuine part serves as the mechanical interface between the transmission output shaft and the driveshaft, transferring rotational torque from the gearbox to the vehicle’s axles. Manufactured to ZF’s exacting tolerances, the 4661.303.003 flange ensures precise alignment and secure coupling, preventing vibration and power loss during heavy-duty operation. It mounts directly onto the output shaft within the transmission housing, where it is retained by a central nut and sealed against fluid leakage. For optimal assembly integrity, this flange is often installed alongside the 4661101020: TRANSMISSION HOUSING and the 4661301046: HOUSING II, which together form the structural enclosure of the gearset.
Symptoms of Failure
When the ZF 4661.303.003 OUTPUT FLANGE begins to wear, operators will notice distinct performance issues. Oil seepage around the output shaft seal is the most common early indicator, as a worn flange surface compromises the seal’s contact area. Driveline vibration during acceleration occurs when the flange’s splines or pilot bore become worn, causing rotational imbalance. Intermittent gear slipping or harsh engagement can result from excessive axial play in the flange, which misaligns the output shaft within the planetary gearset. Visible metal debris in the transmission fluid often accompanies advanced flange wear, indicating spline fretting or galling against the mating shaft.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4661.303.003 |
| OEM Reference | ZF 4661 303 003 |
| Material | Forged Alloy Steel (induction-hardened) |
| Overall Diameter | 185 mm |
| Pilot Bore Diameter | 45 mm |
| Bolt Hole PCD | 150 mm |
| Number of Bolt Holes | 8 |
| Spline Count | 24 (internal) |
| Weight | 2.8 kg |
| Surface Finish | Black oxide / phosphate coated |
Compatibility
This output flange is primarily designed for the ZF WG 90 Series transmission, but its spline geometry and bolt pattern also make it compatible with several other ZF powershift models. Verified applications include the WG 90, WG 120, and WG 150 series. In certain configurations, it can be retrofitted to WG 180 and WG 200 transmissions when used with the correct 0631306174: CYLINDRICAL PIN for alignment. Always confirm the output shaft spline count and pilot bore dimensions against your specific transmission variant before installation. The flange interfaces directly with the 4661301093: TUBE, which routes lubrication oil to the output bearing.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4661101020 | TRANSMISSION HOUSING | Main structural casing for gearset |
| 4661301046 | HOUSING II | Rear housing section supporting output shaft |
| 4661301093 | TUBE | Oil delivery tube to output bearing |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 0769123894 | TYPE PLATE | Identification plate for transmission model |
| 0750100022 | SCREW PLUG | Sealing plug for oil drain port |
| 0636302602 | SCREW PLUG | Magnetic plug for debris collection |
| 0634100633 | O-RING | Seal between flange and shaft |
| 4661301041 | NOZZLE | Lubrication jet for planetary gears |
| 4661301038 | NOZZLE | Secondary lubrication nozzle for clutch pack |
