Overview
The ZF 4644.026.239 6 WG 200(555/3) 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 elements into a single, ready-to-install package. As the core of the WG 200 series, it manages torque distribution across six forward speeds and three reverse ranges. The SKU 4644.026.239 is a direct OEM replacement, ensuring precise fitment and eliminating the need for piecemeal repairs. When installing this assembly, it is critical to pair it with a properly sealed TRANSMISSION HOUSING to prevent contamination and maintain structural integrity.
Symptoms of Failure
When the ZF 4644.026.239 assembly begins to fail, operators typically notice these specific issues:
- Delayed or harsh engagement: A noticeable lag when shifting from neutral to forward or reverse, often accompanied by a clunking sound, indicating worn clutch discs or hydraulic pressure loss.
- Intermittent gear slipping under load: The transmission suddenly loses power during uphill climbs or heavy hauling, then re-engages abruptly—a classic sign of fatigued internal seals or damaged planetary gears.
- External oil seepage at the bell housing: Fluid leaks near the joint between the transmission and the engine, often traced back to a compromised DISCONNECTION component or a cracked housing.
- Overheating with burnt fluid odor: Continuous high-temperature operation caused by internal friction from worn bearings or blocked oil passages, leading to accelerated degradation of the entire unit.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.026.239 |
| Series | WG 200 (6 WG 200/555/3) |
| Assembly Type | Complete Powershift Transmission |
| Dry Weight (approx.) | 385 kg (849 lbs) |
| Housing Material | High-tensile cast iron |
| Input Torque Capacity | 2,000 Nm (1,475 lb-ft) |
| OEM Reference | ZF 4644.026.239 |
| Related Output Flange | 4644303547: OUTPUT FLANGE |
| Alternate Output Flange | 4644303012: OUTPUT FLANGE |
Compatibility
This complete unit is engineered for the ZF WG 200 series, specifically the 6 WG 200(555/3) variant. It is directly compatible with WG 180, WG 200, and WG 210 transmission models used in agricultural tractors, wheel loaders, and industrial forklifts. The assembly also fits select ZF Ergopower and Ecolife derivatives that share the same bell housing pattern. For proper installation, ensure the 4644301240: TRANSMISSION HOUSING is free of cracks and that the 0730365067: TYPE PLATE matches your vehicle’s serial number.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105417 | DISCONNECTION | Clutch disengagement mechanism for PTO |
| 4644303547 | OUTPUT FLANGE | Connects driveshaft to transmission output |
| 4644303012 | OUTPUT FLANGE | Alternate splined output coupling |
| 4644101121 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301240 | TRANSMISSION HOUSING | Replacement housing for WG 200 series |
| 0730365067 | TYPE PLATE | Identification plate with serial number |
| 0631311009 | GROOVED STUD | Fastener for housing alignment |
| 4644301286 | COVER PLATE | Seals access port on transmission |
| 4644301242 | COVER SHEET | Thin protective cover for valve body |
| 0636101026 | CAP SCREW | High-strength bolt for assembly |
