Overview
The ZF 4644.026.329 WENDEGETRIEBE Powershift Transmission Assembly is a complete, factory-sealed unit designed for heavy-duty industrial drivelines. This assembly, identified by SKU 4644.026.329, serves as the primary directional and speed control module within the WG 200 Series transmission family. It integrates the reversing gear set (WENDEGETRIEBE) with the clutch pack housing, enabling seamless forward-to-reverse shifts under load without requiring the vehicle to stop. As a complete unit, it replaces the entire rotating assembly, including the input shaft, planetary gears, and hydraulic piston actuators, ensuring full torque capacity restoration in ZF powershift systems.
Symptoms of Failure
When the ZF 4644.026.329 assembly begins to degrade, operators will notice distinct operational faults. Delayed or harsh directional engagement is a primary indicator, where shifting from forward to reverse produces a noticeable lag or a violent jolt, often accompanied by a loud clunk. Hydraulic oil leaks from the bell housing or shift cylinder area are common, typically presenting as drips or wet spots around the input shaft seal and piston bore. Another critical symptom is intermittent gear slippage under heavy load, where the transmission momentarily loses drive power during acceleration or when climbing grades, indicating worn clutch discs or damaged piston seals. Finally, abnormal whining or grinding noises during directional changes suggest bearing wear or planetary gear scoring within the assembly.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number / SKU | 4644.026.329 |
| Assembly Type | Complete WENDEGETRIEBE Unit (Powershift) |
| Overall Length | 385 mm (15.2 in) |
| Flange Diameter | 280 mm (11.0 in) |
| Dry Weight | 42.5 kg (93.7 lbs) |
| Housing Material | High-Grade Cast Iron (GGG-40) |
| Clutch Disc Material | Sintered Bronze on Steel |
| Max Input Torque | 1,200 Nm (885 lb-ft) |
| OEM Reference | ZF 4644.026.329 (Original) |
Compatibility
This complete unit is engineered specifically for the ZF WG 200 Series powershift transmission family. It is a direct replacement for assemblies found in the following models:
- ZF WG 180 (all sub-variants with WENDEGETRIEBE option)
- ZF WG 200 (standard and high-torque variants)
- ZF WG 210 (select configurations using the 200-series reversing gear)
Important: While the 4644.026.329 is the primary fit for WG200 models, it may also be cross-compatible with certain WG 150 and WG 250 series transmissions that share the same bell housing pattern and spline count. Always verify the input shaft spline count (typically 14-tooth or 21-tooth) and the hydraulic port configuration before installation. For non-WG series applications, consult the original equipment manufacturer’s parts catalog.
