Overview
The ZF 4644.026.288 6 WG 200(555/5) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty industrial drivetrains. This assembly integrates the main gear cluster, clutch packs, and hydraulic control components into a single, ready-to-install package. As the core of the WG 200 Series, it manages torque distribution across six forward and one reverse gear, enabling smooth, power-on shifts under load. The SKU 4644.026.288 identifies this specific 555/5 ratio variant, which is critical for matching output speed to your application. For a complete rebuild, this assembly must be paired with a compatible 4644101223: TRANSMISSION HOUSING to ensure correct alignment of all internal components.
Symptoms of Failure
- Delayed or harsh engagement when shifting from neutral to forward/reverse: Worn clutch discs or degraded seals inside the assembly cause a lag or a jarring clunk, indicating internal hydraulic pressure loss.
- Intermittent gear slipping under heavy load: The transmission may momentarily lose power delivery during uphill climbs or when towing, a classic sign of worn friction plates or a failing torque converter lock-up.
- Contaminated or burnt-smelling transmission fluid: Metal particles or a burnt odor in the oil point to internal wear of the planetary gears or clutch packs, often accompanied by a visible leak around the 4644301298: COVER PLATE.
- Erratic shift patterns or failure to engage a specific gear: A failing shift valve or broken spring within the assembly prevents the transmission from selecting a particular ratio, often requiring immediate replacement of the complete unit.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (SKU) | 4644.026.288 |
| Assembly Type | Complete Powershift Transmission Unit |
| Series | WG 200 (6 WG 200) |
| Gear Ratio | 555/5 (Custom Ratio) |
| Estimated Weight | 185 kg (408 lbs) |
| Housing Material | High-Strength Cast Iron |
| OEM Reference | ZF 4644.026.288 |
| Seal Kit Required | 0634306525: O-RING and 0636305026: SCREW PLUG |
| Internal Filter | 4644301279: SCREEN SHEET |
| Vent/Seal | 4644301088: SEALING CAP |
| Control System | 4644106300: SHIFT SYSTEM |
| Additional Cover | 4644306500: COVER PLATE |
Compatibility
This ZF 4644.026.288 assembly is engineered for the WG 200 Series transmissions, specifically the 6 WG 200 variant with the 555/5 ratio. It is directly compatible with models in the WG180, WG200, and WG210 families that share the same bellhousing pattern and input shaft spline count. The unit also fits select off-highway vehicles and industrial loaders originally equipped with ZF 4WG-200 or 6WG-200 powertrains. Always verify your existing 0730365125: TYPE PLATE to confirm the exact series designation before ordering. For housing replacements, use the 4644301225: TRANSMISSION HOUSING variant for later production runs.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101223 | TRANSMISSION HOUSING | Main structural casing for gear and shaft alignment |
| 4644301225 | TRANSMISSION HOUSING | Alternate housing variant for later series |
| 0730365125 | TYPE PLATE | Identification plate with serial and ratio data |
| 4644301298 | COVER PLATE | Seals the rear access port for clutch inspection |
| 0634306525 | O-RING | Hydraulic seal for fluid passages |
| 0636305026 | SCREW PLUG | Threaded plug for drain or test ports |
| 4644301279 | SCREEN SHEET | Fine mesh filter for hydraulic oil |
| 4644301088 | SEALING CAP | Protective cap for breather or sensor ports |
| 4644106300 | SHIFT SYSTEM | Hydraulic valve body for gear selection |
| 4644306500 | COVER PLATE | Secondary cover for shift system access |
