Overview
The ZF 4660.203.006 OUTPUT FLANGE is a critical driveline component engineered for the WG 98 Series transmission. This OEM genuine part serves as the mechanical interface between the transmission output shaft and the propeller shaft or drive axle, transferring rotational torque from the gearbox to the vehicle’s drivetrain. Positioned at the rear of the transmission housing, the output flange must maintain precise concentricity and spline engagement to prevent vibration and power loss. The SKU 4660.203.006 is manufactured to ZF’s original specifications, ensuring a direct bolt-on replacement without modification. When installed alongside the 4660101017: TRANSMISSION HOUSING and the 4660301054: HOUSING II, this flange completes the sealed output assembly, protecting internal components from contamination.
Symptoms of Failure
Recognizing early signs of output flange wear can prevent catastrophic driveline failure. Watch for these specific symptoms:
- Transmission oil leak at rear seal – A worn flange surface or damaged sealing lip allows ATF to weep past the output shaft seal, leaving puddles under the vehicle.
- Vibration during acceleration – Spline wear or flange runout causes driveline shudder, particularly between 30-50 mph, indicating the flange no longer rotates true.
- Clunking noise on gear engagement – Excessive play between the flange splines and output shaft creates a metallic knock when shifting from Park to Drive or Reverse.
- Driveline binding or hard shifting – A distorted flange can misalign the propeller shaft, placing axial load on the transmission and causing delayed or harsh shifts.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4660.203.006 |
| OEM Reference | ZF 4660.203.006 |
| Material | Forged steel, induction-hardened spline |
| Weight | Approx. 2.8 kg (6.2 lbs) |
| Flange Diameter | 120 mm |
| Pilot Bore | 45 mm |
| Spline Count | 24-tooth, involute profile |
| Bolt Pattern | 6 x M12 on 90 mm PCD |
Compatibility
This output flange is specifically designed for the ZF WG 98 Series transmissions. Based on the spline geometry and bolt pattern, it is compatible with the following ZF models: WG180, WG200, and WG98 variants used in medium-duty trucks, buses, and off-highway equipment. It also fits select Ecomat 4HP and 6HP series where the output shaft diameter matches. Always verify the spline count and pilot bore against your existing flange before ordering. The 0631306174: CYLINDRICAL PIN is required to align the flange during installation, and the 0769123894: TYPE PLATE should be transferred to the new flange for proper identification.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660101017 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4660301054 | HOUSING II | Rear housing section supporting output shaft |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for flange centering |
| 0769123894 | TYPE PLATE | Identification plate with transmission specs |
| 0750100022 | SCREW PLUG | Seals oil passages in housing |
| 4660221029 | SUCTION TUBE | Oil pickup tube for pump supply |
| 0634100317 | O-RING | Seals flange-to-housing joint |
| 0636103273 | CAP SCREW | Fastener for flange retention |
| 0634306311 | O-RING | Seals suction tube connection |
| 4660321029 | FIXING PLATE | Locks flange bolts in position |
