Overview
The ZF 4644.026.011 6 WG 200(555) Powershift Transmission Assembly is a complete, factory-matched unit designed for heavy-duty off-highway applications. 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 drivetrain, it manages torque distribution across six forward speeds and one reverse, ensuring smooth power delivery under extreme loads. The SKU 4644.026.011 is a direct replacement for worn or failed assemblies, eliminating the need for piecemeal repairs. It interfaces directly with the 4460115043: HOUSING to protect internal components from debris and thermal stress.
Symptoms of Failure
- Delayed or harsh gear engagement: When the assembly wears, hydraulic pressure drops, causing a noticeable lag or clunk when shifting from neutral to drive or reverse.
- Torque converter shudder under load: Worn clutch discs or seal degradation inside the 4644.026.011 leads to vibration during acceleration, especially on inclines.
- External oil leaks near the bell housing: Degraded gaskets or cracked housing interfaces allow transmission fluid to escape, often pooling under the vehicle after extended operation.
- Intermittent loss of forward or reverse gears: Internal wear on the planetary gear sets or valve body spools causes the transmission to drop out of gear unexpectedly, a common issue with high-hour units.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4644.026.011 |
| Assembly Type | 6 WG 200(555) Powershift |
| Dry Weight (approx.) | 385 kg (849 lbs) |
| Overall Length | 720 mm |
| Input Torque Capacity | 2,000 Nm (1,475 lb-ft) |
| Housing Material | Cast Iron (GGG-40) |
| OEM Reference | ZF 4644.026.011 |
| Seal Kit Compatible | 0734319337: SHAFT SEAL |
Compatibility
This complete unit is engineered for the ZF WG 200 series, specifically the 6 WG 200(555) variant. It is also compatible with earlier WG 180 and WG 190 models when used with the appropriate adapter kit. The assembly directly replaces units in ZF 4 WG 200 and 6 WG 200 configurations found in loaders, graders, and dump trucks. For proper alignment, always pair this unit with the 4469315012: AXLE DRIVE HOUSING to ensure correct driveline geometry. Internal rotating components, such as the 0750117406: TAPER ROLLER BEARING and the 0750117802: TAPERED ROLLER BEARING, must be inspected during installation to prevent premature failure.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4460115043 | HOUSING | Encloses the gear train and supports bearing loads |
| 4469315012 | AXLE DRIVE HOUSING | Connects transmission output to the differential |
| 0750117406 | TAPER ROLLER BEARING | Supports radial and axial loads on the main shaft |
| 0750117802 | TAPERED ROLLER BEARING | Handles thrust loads from the planetary carrier |
| 0734319337 | SHAFT SEAL | Prevents fluid leakage at the output shaft |
| 0730161317 | WASHER | Spacing and load distribution for clutch pack |
| 0730161451 | WASHER | Thrust washer for planetary gear set |
| 0730161452 | WASHER | Adjustment shim for bearing preload |
| 0730161453 | WASHER | Spacer for output flange alignment |
| 0730161340 | WASHER | Lock washer for retaining nut |
