Overview
The ZF 4644.036.037 6 WG 201 Powershift Transmission Assembly is a complete, factory-grade unit designed for heavy-duty off-highway machinery. This fully assembled transmission serves as the primary power transfer module, integrating the torque converter, planetary gear sets, and clutch packs within a single housing. As a direct replacement for the WG 201 series, the SKU 4644.036.037 ensures seamless integration with your existing driveline, eliminating the need for partial rebuilds or component matching. It sits as the central drivetrain component between the engine and the final drive, converting hydraulic power into precise mechanical output for loaders, graders, and industrial vehicles.
Symptoms of Failure
When the ZF 4644.036.037 assembly begins to fail, operators often notice specific performance declines. Look for these common failure indicators:
- Delayed engagement or gear slipping under load: The transmission hesitates before moving or loses torque when climbing gradients, indicating worn clutch packs or hydraulic pressure loss.
- External oil leaks at housing seams: Fluid weeping from the main casing or around the TRANSMISSION HOUSING (part 4644101203) suggests gasket failure or housing cracks.
- Abnormal whining or grinding noises: High-pitched sounds during shifting point to bearing degradation or debris contamination within the planetary gears.
- Overheating and erratic shifting: The transmission enters limp mode or fails to shift smoothly, often tied to blocked oil passages or a failing torque converter.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4644.036.037 |
| Assembly Type | Complete Powershift Transmission Unit |
| Series | WG 201 (6-speed) |
| Dry Weight (approx.) | 285 kg (628 lbs) |
| Overall Length | 720 mm |
| Overall Width | 510 mm |
| Overall Height | 580 mm |
| Housing Material | High-grade cast iron |
| OEM Reference | ZF 6 WG 201 |
| Torque Capacity | Up to 1,200 Nm |
Compatibility
This complete unit is engineered specifically for the ZF WG 201 series, but it also shares mounting patterns and hydraulic interfaces with the WG 180 and WG 200 families. It is a direct fit for models including the 6 WG 180, 6 WG 200, and 6 WG 201 transmissions used in construction equipment such as wheel loaders and telescopic handlers. For proper sealing and structural integrity, this assembly requires the TRANSMISSION HOUSING (part 4644301382) and the THREADED BUSH (part 4644301189) for oil gallery connections. Additionally, the SCREW PLUG (part 0636302005) is essential for sealing the drain port during installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101203 | TRANSMISSION HOUSING | Main structural casing for gear and shaft support |
| 4644301382 | TRANSMISSION HOUSING | Secondary housing section for clutch pack enclosure |
| 4644301189 | THREADED BUSH | Oil passage connector for hydraulic circuit integrity |
| 0636302005 | SCREW PLUG | Seals drain and fill ports against leakage |
| 0634306198 | O-RING | Provides static seal between housing flanges |
| 0634801098 | SEALING RING | Prevents fluid bypass at shaft interfaces |
| 0730365067 | TYPE PLATE | Identification tag for transmission model and serial |
| 0631311009 | GROOVED STUD | Locating pin for precise housing alignment |
| 4644301161 | COVER PLATE | Encloses access port for valve body inspection |
| 0636100621 | HEXAGON SCREW | Fastener for securing cover plates and flanges |
