Overview
The ZF 4644.026.211 6 WG 200(500) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. This assembly serves as the core power transfer module within the WG 200 series, integrating the torque converter, clutch packs, and planetary gear sets into a single, ready-to-install package. The SKU 4644.026.211 is engineered to replace worn or failed assemblies in wheel loaders, dump trucks, and material handlers, ensuring seamless gear engagement under load. It sits directly between the engine flywheel and the driveline, converting hydraulic power into mechanical torque. For optimal installation, this unit must be paired with a properly torqued 4644105475 DISCONNECTION coupling and a secure 4642303097 OUTPUT FLANGE to transfer power to the axle.
Symptoms of Failure
- Delayed engagement or gear slipping under load: When the 4644.026.211 assembly wears, internal clutch pack clearances increase, causing hesitation when shifting from neutral to forward or reverse. Operators often report a “flare” in RPM before the gear catches.
- External oil leaks near the bell housing: Degraded seals within the transmission assembly allow hydraulic fluid to escape, leaving puddles under the vehicle. This symptom is frequently searched as “ZF WG200 oil leak at housing joint.”
- Erratic shifting or harsh engagement: Worn valve body components inside the assembly cause pressure fluctuations, resulting in jarring shifts. This is often described as “ZF powershift jerking when accelerating.”
- Overheating transmission fluid: Internal wear generates excessive friction, raising fluid temperatures beyond normal operating ranges. This symptom is commonly queried as “ZF 6 WG 200 overheating causes.”
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.026.211 |
| Assembly Type | Complete Powershift Unit (6-speed) |
| Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | High-strength cast iron |
| Input Torque Capacity | 500 Nm (369 lb-ft) |
| OEM Reference | ZF 6 WG 200(500) |
| Mounting Bolt Torque | Use 0636020211 HEXAGON SCREW (M12 x 1.5, grade 10.9) |
| Housing Part | 4644101134 TRANSMISSION HOUSING |
Compatibility
This complete unit is specifically engineered for the ZF WG 200 series, including the WG180, WG200, and WG250 variants. It is a direct fit for 6 WG 200(500) applications found in models such as the ZF 6WG200, 6WG180, and 6WG250. The assembly is also backward-compatible with earlier WG 200 series transmissions when paired with the correct TRANSMISSION HOUSING. Always verify the bell housing pattern and output flange spline count before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105475 | DISCONNECTION | Coupling between engine and transmission |
| 4642303097 | OUTPUT FLANGE | Connects transmission to driveshaft |
| 0636020211 | HEXAGON SCREW | Mounting fastener for housing |
| 4644101134 | TRANSMISSION HOUSING | Main structural casing |
| 4644301349 | HOUSING | Secondary cover housing |
| 0730365125 | TYPE PLATE | Identification and rating plate |
| 0631311009 | GROOVED STUD | Alignment stud for assembly |
| 0636305019 | SCREW PLUG | Seals fluid passages |
| 4644301247 | THREADED BUSH | Wear-resistant bushing for linkage |
| 0634303485 | O-RING | Hydraulic seal for joints |
