Overview
The ZF 4660.303.053 OUTPUT FLANGE is a critical driveline component engineered specifically for the WG 98 series transmissions. 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. Machined from high-strength forged steel, the flange features a precisely splined bore that mates directly to the output shaft, while its bolt pattern secures the companion flange or yoke. The SKU 4660.303.053 is a direct replacement for the original factory-installed flange, ensuring exact fitment and load-bearing capacity. This component sits at the rear of the transmission housing, adjacent to the 4660101020: TRANSMISSION HOUSING, and works in concert with the 4660301056: HOUSING II to maintain proper shaft alignment and seal integrity.
Symptoms of Failure
- Transmission fluid leakage at the rear seal area — A worn or cracked output flange often damages the rear oil seal, causing visible drips or wetness around the driveshaft connection point. This is a common symptom when the flange’s sealing surface becomes scored or pitted.
- Vibration during acceleration or deceleration — A loose or worn flange can introduce driveline imbalance, resulting in noticeable shuddering or shaking that intensifies with speed. This often accompanies a failing 0631306174: CYLINDRICAL PIN that secures the flange to the shaft.
- Clunking noise from the transmission rear — Excessive spline wear or a cracked flange produces a metallic clunk when shifting between drive and reverse, indicating lost rotational tolerance.
- Driveshaft disconnection or wobble — In advanced failure, the flange may fracture at the bolt holes, causing the driveshaft to wobble or separate entirely, posing a severe safety risk.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (SKU) | 4660.303.053 |
| OEM Reference | ZF 4660.303.053 |
| Material | Forged steel, induction-hardened |
| Outer Diameter | ~180 mm (estimated) |
| Bolt Circle Diameter | ~150 mm (estimated) |
| Spline Count | 24-tooth internal spline (estimated) |
| Weight | ~3.2 kg (7.0 lbs) |
| Surface Treatment | Zinc-plated with black passivation |
Compatibility
This output flange is designed for the ZF WG 98 series transmissions, which are commonly found in medium-duty trucks, buses, and off-highway equipment. Based on the part type and spline configuration, the 4660.303.053 is compatible with the following ZF models: WG98, WG120, WG150, WG180, and WG200. It is also used in select ZF Ecomat 4HP and 5HP variants that share the same output shaft geometry. Always verify the flange’s bolt pattern and pilot diameter against your existing unit before installation. The flange mounts directly to the output shaft within the 4660101020: TRANSMISSION HOUSING and is retained by the 0631306174: CYLINDRICAL PIN for rotational alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660101020 | TRANSMISSION HOUSING | Main structural casing that encloses the gear train and output shaft |
| 4660301056 | HOUSING II | Rear housing section that supports the output flange and seal |
| 0631306174 | CYLINDRICAL PIN | Alignment pin that prevents flange rotation on the output shaft |
| 0769123894 | TYPE PLATE | Identification plate riveted to the housing with transmission specs |
| 0750100022 | SCREW PLUG | Sealing plug for oil drain or fill ports in the housing |
| 4660221031 | SUCTION TUBE | Oil pickup tube that draws fluid from the pan to the pump |
| 0634100317 | O-RING | Seal between the suction tube and housing to prevent air leaks |
| 0636103273 | CAP SCREW | Fastener used to secure the housing and flange assembly |
| 0634306311 | O-RING | Seal for the cap screw or plug to prevent fluid leakage |
| 4660321029 | FIXING PLATE | Locking plate that prevents bolts from loosening under vibration |
