Overview
The ZF 4644.033.037 3 WG 201 Powershift Transmission Assembly is a complete, factory-matched unit engineered for heavy-duty off-highway applications. This assembly integrates the planetary gear set, clutch packs, and hydraulic control components into a single, ready-to-install package. As a direct replacement for the WG 201 series, the SKU 4644.033.037 ensures precise gear engagement under load, making it critical for wheel loaders, dozers, and material handlers. The unit sits at the heart of the driveline, transferring torque from the engine to the axles through a multi-speed powershift configuration. For optimal sealing and structural integrity, this assembly is designed to pair with the TRANSMISSION HOUSING (4644101160) and the TRANSMISSION HOUSING (4644301323), which provide the rigid casing required for high-torque operations.
Symptoms of Failure
- Delayed or harsh shifting under load: Worn clutch discs or hydraulic seal degradation inside the 4644.033.037 cause hesitation or jarring engagement, especially when transitioning between forward and reverse gears.
- Oil leaks from the main housing interface: Fatigue in the gasket or seal surfaces leads to visible fluid seepage around the transmission bell housing, often accompanied by a burnt smell from overheated oil.
- Gear slipping during uphill operation: Internal pressure loss from a failing pump or valve body results in the transmission dropping out of gear under heavy torque, reducing machine productivity.
- Unusual whining or grinding noises: Bearing wear or debris contamination within the assembly produces metallic sounds that intensify with engine RPM, indicating imminent internal damage.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.033.037 |
| Assembly Type | Complete Powershift Transmission Unit (3 WG 201) |
| Weight (estimated) | 185 kg (408 lbs) |
| Dimensions (L x W x H) | 620 mm x 480 mm x 420 mm |
| Housing Material | High-strength cast iron (GGG-40) |
| OEM Reference | ZF WG 201 Series |
| Torque Capacity | Up to 1,200 Nm |
| Fluid Capacity | 12.5 liters (ZF TE-ML 03 spec) |
Compatibility
This complete unit is specifically designed for the ZF WG 201 transmission series, which includes models such as the WG180, WG200, and WG210. It is commonly found in articulated dump trucks, wheel loaders, and telescopic handlers from manufacturers like Liebherr, Volvo, and Caterpillar. The 4644.033.037 assembly is also backward-compatible with select WG 180 variants when used with the appropriate THREADED BUSH (4644301189) and SCREW PLUG (4475280043) for pressure port sealing. Always verify the bell housing pattern and input shaft spline count before installation.
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 enclosure |
| 4644301189 | THREADED BUSH | Wear-resistant insert for hydraulic line connections |
| 4475280043 | SCREW PLUG | Sealing plug for oil gallery access ports |
| 0634306198 | O-RING | Elastomeric seal for fluid-tight joints |
| 0730365067 | TYPE PLATE | Identification label with serial number |
| 4644301161 | COVER PLATE | Access cover for valve body inspection |
| 0636100621 | HEXAGON SCREW | Fastener for housing assembly |
| 0631610020 | SET SCREW | Adjustable stop for shift fork positioning |
| 0501218540 | BREATHER | Pressure equalization vent for thermal expansion |
