Overview
The ZF 4644.033.008 3 WG 201 Powershift Transmission Assembly | Complete Unit is a fully integrated, factory-matched assembly designed for heavy-duty off-highway machinery. This complete unit serves as the core power transfer module within the WG 201 Series, managing torque distribution across multiple gear ranges. As a drop-in replacement, the SKU 4644.033.008 eliminates the need for piecemeal rebuilding, ensuring precise clutch pack alignment and hydraulic circuit integrity. It sits directly between the engine bell housing and the final drive, integrating the torque converter, planetary gear sets, and valve body into a single sealed unit.
Symptoms of Failure
- Erratic gear engagement or slipping under load: Worn clutch discs or degraded seals inside the assembly cause delayed shifts or complete loss of drive in specific ranges, often accompanied by a burning smell.
- Hydraulic fluid contamination or overheating: Internal debris from a failing unit can clog the valve body, leading to erratic pressure spikes and transmission fluid temperatures exceeding 120°C (248°F).
- Audible whining or grinding from the transmission housing: Bearing fatigue or planetary gear damage within the assembly produces a distinct metallic noise, particularly during deceleration or low-speed maneuvering.
- External oil seepage at mating surfaces: Cracks in the TRANSMISSION HOUSING or worn gaskets around the TRANSMISSION HOUSING allow fluid loss, leading to low pressure and eventual unit seizure.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number / SKU | 4644.033.008 |
| Assembly Type | Complete Powershift Unit (3 WG 201) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF 4644.033.008 |
| Max Input Torque | 1,200 Nm |
| Hydraulic Pressure Range | 14–22 bar |
Compatibility
This complete assembly is engineered for the WG 201 Series powershift transmissions. It is directly compatible with models including the WG180, WG200, and WG211 found in ZF’s off-highway lineup. The unit also fits select variants of the WG160 and WG250 when paired with the correct bell housing adapter. For precise fitment, verify the serial number against your existing transmission tag; the TYPE PLATE provides critical identification data. Always inspect the THREADED BUSH and SCREW PLUG for wear during installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Encloses and supports gear train |
| 4644301323 | TRANSMISSION HOUSING | Alternate housing for specific variants |
| 4644301189 | THREADED BUSH | Provides wear-resistant thread for mounting |
| 4475280043 | SCREW PLUG | Seals hydraulic ports and drain points |
| 0634306198 | O-RING | Prevents fluid leaks at joint interfaces |
| 0730365067 | TYPE PLATE | Identifies transmission model and serial |
| 4644301161 | COVER PLATE | Protects valve body and clutch access |
| 0636100621 | HEXAGON SCREW | Secures housing and cover assemblies |
| 0631610020 | SET SCREW | Adjusts clutch pack preload |
| 0501218540 | BREATHER | Equalizes internal pressure and vents moisture |
