Overview
The ZF 4644.033.033 3 WG 201 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 201 series, it governs torque distribution and speed range selection under load. The SKU 4644.033.033 is a direct OEM replacement, ensuring seamless integration with existing driveline configurations. This unit sits between the torque converter and the output shaft, managing power flow through planetary gear sets. For a complete rebuild, pairing this assembly with a new TRANSMISSION HOUSING (part 4644101160) or a TRANSMISSION HOUSING (part 4644301323) is recommended to eliminate casing wear.
Symptoms of Failure
- Delayed or harsh gear engagement: When the assembly wears, internal clutch pack clearances increase, causing a noticeable lag or bang when shifting from neutral to forward or reverse.
- Progressive gear slipping under load: A worn 4644.033.033 unit will allow the transmission to rev higher than expected without proportional vehicle movement, especially on inclines.
- Metallic debris in the oil filter or pan: Flaking from hardened gear teeth or bearing surfaces produces fine silver or steel particles, indicating imminent internal failure.
- Intermittent loss of drive in specific ranges: A failing assembly may lose power in one gear range (e.g., 3rd gear) while other ranges remain functional, pointing to a damaged planetary carrier.
Technical Specifications
| Parameter | Specification |
|---|---|
| OEM Part Number | 4644.033.033 |
| Series | WG 201 (3 WG 201) |
| Assembly Type | Complete Powershift Unit |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Overall Length | 620 mm |
| Housing Material | High-Grade Cast Iron |
| Clutch Count | 6 (hydraulic actuated) |
| Torque Capacity (max) | 1,200 Nm |
| OEM Reference | ZF 4644.033.033 |
| Sealing Kit Required | O-RING (0634306198) |
| Identification | TYPE PLATE (0730365067) |
| Access Cover | COVER PLATE (4644301161) |
| Mounting Hardware | HEXAGON SCREW (0636100621) |
| Adjustment Screw | SET SCREW (0631610020) |
| Ventilation | BREATHER (0501218540) |
Compatibility
This complete assembly is engineered for the ZF WG 201 series, but it also cross-fits select models in the WG180 and WG200 families due to shared planetary gear architecture. It is a direct drop-in for 3-speed powershift variants used in wheel loaders, forklifts, and agricultural tractors. Always verify the housing interface; the THREADED BUSH (4644301189) and SCREW PLUG (4475280043) are often replaced concurrently to prevent oil migration. Compatible base models include WG180, WG200, and all WG201 sub-variants (2 WG 201, 3 WG 201, 4 WG 201).
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Outer casing for gear and clutch assembly |
| 4644301323 | TRANSMISSION HOUSING | Alternate housing variant for WG series |
| 4644301189 | THREADED BUSH | Seals and guides shift linkage |
| 4475280043 | SCREW PLUG | Closes hydraulic test ports |
| 0634306198 | O-RING | Seals housing joints against leaks |
| 0730365067 | TYPE PLATE | Identification tag for serial number |
| 4644301161 | COVER PLATE | Protects clutch access opening |
| 0636100621 | HEXAGON SCREW | Fastens cover plate to housing |
| 0631610020 | SET SCREW | Locks adjustment mechanisms |
| 0501218540 | BREATHER | Equalizes internal pressure |
