Overview
The ZF 4644.026.275 WENDEGETRIEBE Powershift Transmission Assembly is a complete, factory-sealed unit engineered for the demanding environment of heavy-duty industrial drivetrains. As a core component within the WG 200 Series, this assembly functions as the primary power distribution hub, managing torque flow between the engine and the final drive. The SKU 4644.026.275 specifically denotes a fully assembled reversing gearbox (WENDEGETRIEBE) with integrated hydraulic clutch packs, designed to facilitate seamless directional changes without operator clutch pedal intervention. This unit replaces the need for individual component rebuilds, offering a direct bolt-in solution for maintaining operational uptime in wheel loaders, forklifts, and specialized construction machinery.
Symptoms of Failure
When the ZF 4644.026.275 assembly begins to degrade, operators typically notice distinct performance issues. Recognizing these early signs can prevent catastrophic driveline damage and costly downtime.
- Delayed or Harsh Directional Shifts: A pronounced lag when shifting from forward to reverse, or a violent engagement, indicates worn clutch discs or degraded hydraulic seals within the powershift unit.
- Internal Hydraulic Leaks: Visible oil seepage around the transmission housing bellhousing or cooler line ports suggests compromised gaskets or cracked casting in the 4644.026.275 assembly, leading to low system pressure.
- Gear Slipping Under Load: The transmission momentarily loses power during acceleration or when climbing, often accompanied by a high-pitched whine. This points to worn friction plates or a failing torque converter lock-up clutch inside the unit.
- Overheating Transmission Fluid: Persistent high-temperature readings on the dash gauge, even with adequate fluid levels, signal internal drag from failing bearings or blocked oil passages within the WG 200 series assembly.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number / SKU | 4644.026.275 |
| Assembly Type | Complete Powershift WENDEGETRIEBE (Reversing Unit) |
| Dry Weight (approx.) | 185 kg (408 lbs) |
| Housing Material | High-Tensile Cast Iron (GGG-40) |
| Input Torque Capacity | 1,200 Nm (885 lb-ft) |
| Hydraulic Pressure Range | 18-22 bar (261-319 psi) |
| OEM Reference | ZF 4644.026.275 (Direct Replacement) |
| Overall Length | 620 mm (24.4 in) |
| Mounting Flange Diameter | SAE 3 (Standard) |
Compatibility
This complete unit is engineered for the ZF WG 200 Series transmission family. It is a direct fit for models including the WG180, WG200, and WG210 variants commonly found in industrial powertrains. The 4644.026.275 assembly is specifically designed for applications requiring a reversing gearbox with integrated powershift functionality. It is compatible with machines originally equipped with ZF 4WG-200, 4WG-180, and 4WG-210 transmissions. Always verify the bellhousing pattern and input shaft spline count against your existing unit to ensure proper fitment.
Common Compatible Machine Types
- Articulated Dump Trucks (ADTs) with ZF WG200 drivelines
- Heavy-duty Forklifts (10-18 ton capacity)
- Wheel Loaders (mid-size to large frame)
- Industrial Telehandlers with powershift requirements
