Overview
The ZF 4644.026.242 6 WG 200(555) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly integrates the planetary gear sets, clutch packs, and hydraulic control components into a single, ready-to-install package. As a core element of the WG 200 series, the SKU 4644.026.242 replaces the need for piecemeal repairs, ensuring precise gear engagement under high torque loads. It sits at the heart of the driveline, converting engine power into controlled motion for wheel loaders, dozers, and graders. The unit is typically paired with a TRANSMISSION HOUSING to form the main structural shell, and it relies on a TYPE PLATE for accurate OEM identification during installation.
Symptoms of Failure
- Delayed or harsh shifting under load: When the internal clutch discs or seals degrade, operators often experience a noticeable lag between gear selection and engagement, particularly when the transmission is hot.
- Low hydraulic pressure and erratic operation: Worn valve bodies or piston seals within the assembly can cause pressure drops, leading to gear slippage or unexpected neutral conditions during uphill travel.
- Metallic debris in the oil pan: Advanced wear of planetary gears or thrust washers produces fine metal particles. This contamination often clogs the filter and accelerates damage to the TRANSMISSION HOUSING and associated bearings.
- External oil seepage at the bell housing: A failing input shaft seal or cracked housing gasket allows transmission fluid to escape, reducing lubrication and causing overheating.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4644.026.242 |
| Assembly Type | Complete Powershift Unit (6 WG 200) |
| Weight (estimated) | 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Housing Material | High-strength cast iron |
| Max Input Torque | 555 Nm |
| Number of Speeds | 6 forward / 3 reverse |
| Mounting Configuration | SAE 3 bell housing |
| Related Seal Kit | SEALING RING (0634801250) |
| Related Plug Kit | SCREW PLUG (0636305026) |
Compatibility
This complete assembly is engineered for the ZF WG 200 series, including the WG200, WG180, and WG150 variants used in construction and material handling equipment. It directly replaces units with the 555 Nm torque rating. The assembly is compatible with both standard and high-flow hydraulic systems. For proper installation, ensure the GROOVED STUD is torqued to specification to secure the housing. Additionally, the COVER PLATE (4644303060) and COVER PLATE (4644303061) are often replaced concurrently to prevent leaks. Always verify the serial number against the TYPE PLATE for exact model matching.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101102 | TRANSMISSION HOUSING | Main structural casing for gear sets |
| 4644301195 | TRANSMISSION HOUSING | Alternate housing variant for WG200 |
| 0730365067 | TYPE PLATE | Identification tag for serial number |
| 0631311009 | GROOVED STUD | Fastener for housing alignment |
| 4644303060 | COVER PLATE | Seals the clutch access port |
| 4644303061 | COVER PLATE | Alternate cover plate for PTO side |
| 0634801250 | SEALING RING | Prevents oil leaks at shaft joints |
| 0636305026 | SCREW PLUG | Closes hydraulic test ports |
| 0636305019 | SCREW PLUG | Magnetic plug for oil pan |
| 0634801165 | SEALING RING | O-ring for valve body cover |
