Overview
The ZF 4660.302.012 STATOR SHAFT is a critical internal component engineered for the WG200, WG92, and WG98 series transmissions. This genuine OEM part serves as the central torque-reaction element within the torque converter assembly, channeling hydraulic fluid flow and providing the necessary mechanical support for the stator clutch. Positioned between the turbine and pump, the stator shaft ensures proper torque multiplication during launch and low-speed operation. The SKU 4660.302.012 is precision-machined to ZF’s exacting tolerances, making it a direct replacement for worn units in heavy-duty commercial and industrial drivelines.
Symptoms of Failure
- Delayed or erratic gear engagement: A worn stator shaft can cause insufficient hydraulic pressure, leading to hesitation when shifting from neutral to drive or reverse.
- Torque converter shudder or vibration: Excessive clearance in the stator shaft splines or bearing surfaces produces noticeable shudder during acceleration, especially under load.
- Low transmission fluid pressure warnings: Internal leakage past a scored stator shaft reduces pump output, triggering dashboard alerts or diagnostic trouble codes.
- Metallic debris in the oil pan: Flaking or spalling on the stator shaft surface contaminates the fluid, often accompanied by a whining noise from the converter area.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4660.302.012 |
| Material | Case-hardened alloy steel (16MnCr5 equivalent) |
| Overall Length | 185 mm (estimated) |
| Outer Diameter (bearing journal) | 42 mm |
| Spline Count | 27 internal splines |
| Dry Weight | 0.85 kg |
| OEM Reference | ZF 4660.302.012 |
| Surface Finish | Ground and polished (Ra ≤ 0.4 µm) |
Compatibility
This stator shaft is specifically designed for ZF WG180, WG200, WG92, and WG98 series transmissions. It also fits select variants of the WG150 and WG210 where the torque converter stator support geometry matches. Always verify the spline count and bearing journal dimensions against your existing shaft before installation. The part integrates directly with the 4660101011: TRANSMISSION HOUSING and the 4660301018: HOUSING to maintain proper alignment. During rebuilds, it is common to replace the 0501209818: RANGE SELECTOR and inspect the 4660198001: PERIPHERALS kit simultaneously.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660198001 | PERIPHERALS | Seal and gasket kit for transmission rebuild |
| 0501209818 | RANGE SELECTOR | Hydraulic valve for gear range selection |
| 4660101011 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4660301018 | HOUSING | Torque converter housing cover |
| 0631306174 | CYLINDRICAL PIN | Alignment pin for housing assembly |
| 0769123894 | TYPE PLATE | Identification plate with transmission specs |
| 4660221012 | SUCTION TUBE | Oil pick-up tube for pump inlet |
| 0634100317 | O-RING | Static seal for fluid passages |
| 0636103273 | CAP SCREW | Fastener for housing retention |
| 0750100022 | SCREW PLUG | Threaded plug for oil gallery access |
