Overview
The ZF 4660.001.026 WG 92 S 4 Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly serves as the core hydraulic-mechanical power transfer module within the WG 92 Series, integrating the clutch packs, planetary gearsets, and valve body into a single ready-to-install package. The SKU 4660.001.026 specifically denotes a remanufactured or new-build complete assembly, ensuring precise alignment of all internal components for optimal torque delivery and shift quality. It sits directly between the engine bellhousing and the output driveline, replacing the entire rotating assembly to restore factory performance without piecemeal repairs.
Symptoms of Failure
- Delayed or harsh engagement when shifting from neutral to forward/reverse: This indicates worn clutch pack clearances or degraded sealing rings within the assembly, causing hydraulic pressure bleed-off.
- Intermittent loss of drive under load (slipping): A common sign of fatigued friction discs or a failing torque converter stator, often accompanied by elevated transmission oil temperature.
- Metallic grinding or whining noise from the transmission housing: Suggests bearing failure or gear tooth damage inside the assembly, which can rapidly escalate if the unit is not replaced.
- External oil seepage at the main case joint: While often misdiagnosed as a simple gasket issue, persistent leaks may stem from a cracked 4660101012: TRANSMISSION HOUSING or a warped 4660301020: HOUSING that cannot seal properly.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4660.001.026 |
| Assembly Type | Complete Powershift Unit (WG 92 S 4) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Primary Material | High-grade cast iron housing with steel planetary carriers |
| OEM Reference | ZF 4660.001.026 / WG92S4 |
| Fluid Capacity (assembly only) | 12.5 liters (ATF Dexron III) |
| Max Input Torque | 1,200 Nm |
Compatibility
This complete assembly is engineered for the ZF WG 92 Series powershift transmission family. It is directly compatible with models including the WG180, WG200, and WG92 S 4 variants commonly found in telescopic handlers, wheel loaders, and industrial tractors. The unit also fits select WG 92 S 3 configurations with minor adapter modifications. Always verify the existing 0769123894: TYPE PLATE on your transmission to confirm model suffix before installation. For proper alignment during rebuild, the 0631306174: CYLINDRICAL PIN must be replaced to ensure dowel hole registration between the new assembly and the bellhousing.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4660101012 | TRANSMISSION HOUSING | Outer casing that encloses the gear train and oil sump |
| 4660301020 | HOUSING | Intermediate support housing for clutch drum assembly |
| 0631306174 | CYLINDRICAL PIN | Alignment dowel for precise housing-to-case positioning |
| 0769123894 | TYPE PLATE | Identification plate with model and serial number |
| 4660221012 | SUCTION TUBE | Oil pickup tube from sump to pump inlet |
| 0634100317 | O-RING | Seal for hydraulic line connections |
| 0636103273 | CAP SCREW | Fastener for securing housing sections |
| 0750100022 | SCREW PLUG | Threaded plug for oil drain or test ports |
| 4660101804 | TRANSMISSION HOUSING | Alternate housing variant for specific WG92 builds |
| 4660301008 | HOUSING | Compact housing for reduced-length configurations |
