Overview
The ZF 4644.026.286 6 WG 200(555/5) Powershift Transmission Assembly | Complete Unit is a fully assembled drop-in solution designed for heavy-duty off-highway machinery. This complete unit integrates the main gear cluster, clutch packs, and hydraulic control system into a single, pre-tested assembly. As the core power transfer module in the WG 200 series, it replaces the entire internal rotating and shifting mechanism. The SKU 4644.026.286 is specifically calibrated for the 6-speed forward, 1-reverse configuration with a 555/5 ratio set. When installing this unit, ensure the outer 4644101177: TRANSMISSION HOUSING is free of cracks, and verify the 4644301229: TRANSMISSION HOUSING mating surfaces are clean to prevent contamination.
Symptoms of Failure
- Erratic shifting or gear slippage under load: Worn clutch discs or damaged seals inside the assembly cause the transmission to slip when moving heavy loads, especially in 4th and 5th gear.
- Delayed engagement when shifting from neutral to drive: A failing hydraulic control unit within the assembly results in a 3-5 second lag before power is transmitted, indicating internal pressure loss.
- Metallic grinding noise during gear changes: Worn bearings or damaged planetary gears produce a distinct grinding sound, particularly when shifting between forward and reverse.
- Contaminated transmission fluid with metallic debris: Internal component wear sheds metal particles into the oil, often visible on the 4644301279: SCREEN SHEET during routine maintenance.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number / SKU | 4644.026.286 |
| Series | WG 200 (6 WG 200) |
| Configuration | 6 Forward / 1 Reverse (555/5 Ratio) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | High-strength cast iron |
| Input Torque Capacity | 1,200 Nm (885 lb-ft) |
| OEM Reference | ZF 4644.026.286 |
| Fluid Capacity | 12.5 liters (3.3 gallons) |
Compatibility
This complete unit is engineered for the ZF WG 200 series powershift transmissions, commonly found in telehandlers, wheel loaders, and industrial tractors. It is directly compatible with the WG 200(555/5) variant and can be adapted to WG 180 and WG 190 models with specific housing modifications. The assembly integrates with the 0730365067: TYPE PLATE for correct identification and requires the 0631311009: GROOVED STUD for secure mounting to the bell housing. Always cross-reference your existing transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101177 | TRANSMISSION HOUSING | Outer casing for the complete assembly |
| 4644301229 | TRANSMISSION HOUSING | Alternative housing variant for WG 200 |
| 0730365067 | TYPE PLATE | Identification plate for serial number |
| 0631311009 | GROOVED STUD | Mounting stud for bell housing |
| 4644303060 | COVER PLATE | Access cover for clutch inspection |
| 4644303061 | COVER PLATE | Alternate cover plate variant |
| 0634306525 | O-RING | Seal for hydraulic connections |
| 0636305026 | SCREW PLUG | Drain/fill port plug |
| 0501316470 | BREATHER | Pressure equalization vent |
| 4644301279 | SCREEN SHEET | Internal oil filter screen |
