Overview
The ZF 4644.033.018 3 WG 201 Powershift Transmission Assembly | Complete Unit is a fully integrated drop-in solution for heavy-duty off-highway machinery. This complete assembly, identified by SKU 4644.033.018, serves as the core power transfer module within the WG 201 series, managing torque distribution across multiple gear ranges. It integrates the clutch pack, planetary gear sets, and hydraulic control circuits into a single sealed unit. When installing this assembly, ensure the mating TRANSMISSION HOUSING is free of cracks, and verify the alignment of the TRANSMISSION HOUSING to prevent premature wear on the output shaft bearings.
Symptoms of Failure
- Erratic gear engagement under load: When the internal clutch packs wear, operators experience delayed or harsh shifting, particularly when transitioning from forward to reverse in loaders or graders.
- Low hydraulic pressure warnings: A failing assembly often triggers pressure drop alerts due to internal seal degradation, leading to insufficient clutch pack clamping force.
- Metallic debris in transmission fluid: Worn planetary gears or thrust washers produce fine metal particles, visible during routine oil changes, indicating imminent internal failure.
- Oil leaks from the bell housing area: Degraded gaskets or a damaged THREADED BUSH can allow fluid to escape, often mistaken for a simple seal issue when the root cause is the assembly itself.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4644.033.018 |
| Assembly Type | 3 WG 201 Powershift Transmission (Complete Unit) |
| Dry Weight | Approx. 185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF 4644.033.018 / 3 WG 201 |
| Torque Capacity | Up to 1,200 Nm (estimated) |
| Fluid Capacity | 12.5 liters (ZF TE-ML 03 spec) |
| Sealing Components | O-RING (0634306198) and SCREW PLUG (4475280043) |
| Identification | TYPE PLATE (0730365067) included |
Compatibility
This complete assembly is engineered for the ZF WG 201 series powershift transmissions. It is directly compatible with models including the WG180, WG200, and WG210 variants found in telescopic handlers, wheel loaders, and dump trucks. The unit also fits select 3 WG 201 configurations used in agricultural tractors. For proper sealing, always install a new HEXAGON SCREW (0636100621) and SET SCREW (0631610020) during reassembly. Ensure the BREATHER (0501218540) is clear to prevent pressure buildup inside the housing.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4644301323 | TRANSMISSION HOUSING | Secondary housing for clutch pack integration |
| 4644301189 | THREADED BUSH | Provides wear-resistant thread for hydraulic line connections |
| 4475280043 | SCREW PLUG | Seals oil passages during transport and operation |
| 0634306198 | O-RING | Prevents fluid leaks at housing joints |
| 0730365067 | TYPE PLATE | Riveted identification tag for serial number tracking |
| 4644301161 | COVER PLATE | Protects internal valve body from debris ingress |
| 0636100621 | HEXAGON SCREW | Fastens cover plate and housing sections |
| 0631610020 | SET SCREW | Locks adjustment rings on shift forks |
| 0501218540 | BREATHER | Equalizes internal pressure to prevent seal blowout |
