Overview
The ZF 4644.026.393 6 WG 200(555/5) Powershift Transmission Assembly is a complete, ready-to-install unit engineered for heavy-duty off-highway applications. This assembly integrates the main gear train, clutch packs, and hydraulic control system into a single robust package. As a core component of the WG 200 series, it manages torque distribution and speed shifting under extreme loads. The SKU 4644.026.393 is a direct OEM replacement, ensuring seamless integration with existing drivelines. This complete unit eliminates the need for piecemeal repairs, providing a reliable solution for restoring full operational capacity to your equipment.
Symptoms of Failure
When the ZF 4644.026.393 assembly begins to fail, operators typically notice these specific issues:
- Erratic or delayed gear engagement: The transmission hesitates or slams into gear, often accompanied by a loud clunk, indicating worn clutch discs or hydraulic pressure loss within the assembly.
- Torque converter shudder under load: A persistent vibration or shudder during acceleration, especially when moving heavy loads, points to internal wear in the stator or turbine components of this unit.
- External oil seepage from housing joints: Visible fluid leaks around the mating surfaces of the transmission housing or cover plate suggest degraded seals or gaskets, often requiring replacement of the 0634306323: O-RING to stop the leak.
- Loss of power in forward or reverse: A noticeable reduction in pulling power, particularly in one direction, signals internal clutch pack slippage or a failing one-way clutch within the 4644.026.393 assembly.
Technical Specifications
| Part Number / SKU | 4644.026.393 |
| Assembly Type | Complete Powershift Transmission Unit (6 WG 200) |
| Dry Weight (approx.) | 285 kg (628 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 560 mm |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF 6 WG 200(555/5) |
| Input Torque Capacity | 2000 Nm (1475 lb-ft) |
| Number of Speeds | 6 forward / 3 reverse |
Compatibility
This complete assembly is specifically designed for the ZF WG 200 Series powershift transmissions. It is a direct fit for models including the WG 180, WG 200, and WG 211, commonly found in loaders, graders, and industrial tractors. The unit is also compatible with earlier variants of the 6 WG 200(555/5) platform. For proper installation, ensure the 4644101249: TRANSMISSION HOUSING and 4644301402: TRANSMISSION HOUSING are inspected for cracks or warping. The 4644301298: COVER PLATE must also be aligned correctly to prevent oil bypass.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101249 | TRANSMISSION HOUSING | Main structural casing for gear train support |
| 4644301402 | TRANSMISSION HOUSING | Secondary housing section for clutch pack enclosure |
| 4644301298 | COVER PLATE | Seals the valve body and hydraulic passages |
| 0634306323 | O-RING | Prevents fluid leaks at housing interfaces |
| 0636305026 | SCREW PLUG | Seals oil drain and fill ports |
| 4644301279 | SCREEN SHEET | Filters debris from hydraulic fluid |
| 4644301088 | SEALING CAP | Protects sensor ports from contamination |
| 4644109046 | PARKING BRAKE | Electro-hydraulic parking brake assembly |
| 0501216078 | BRAKE | Service brake disc for output shaft |
| 0501298641 | SEAL KIT | Complete gasket and o-ring set for overhaul |
