Overview
The ZF 4644.004.134 WENDEGETRIEBE Powershift Transmission Assembly is a complete, factory-matched unit designed for the demanding environment of industrial drivetrains. As a core component of the WG 180 Series, this assembly integrates the reversing gear group and clutch pack into a single, pre-assembled module. The SKU 4644.004.134 identifies a fully built assembly that replaces the need for individual component stacking, ensuring precise gear engagement and load distribution. It sits directly between the torque converter and the output section, managing directional changes without interrupting power flow. This unit is often paired with the 4644105413 DISCONNECTION to isolate the driveline during maintenance, and it mounts securely to the 4644101222 TRANSMISSION HOUSING for structural integrity.
Symptoms of Failure
When the ZF 4644.004.134 begins to degrade, operators will notice distinct performance issues. Common failure symptoms include:
- Delayed or harsh directional shifts – The transmission hesitates or slams into forward or reverse, indicating worn clutch discs or hydraulic seal leakage within the assembly.
- Oil seepage from the bell housing area – Internal pressure loss causes fluid to escape around the mating surfaces, often linked to a compromised 0634306525 O-RING or housing gasket.
- Intermittent power loss under load – The unit slips during heavy operation, failing to transmit torque consistently, which points to fatigued sprag clutches or worn piston rings.
- Unusual grinding or whining noise – Metallic sounds during gear changes suggest bearing failure or debris contamination inside the assembly.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.004.134 |
| Assembly Type | WENDEGETRIEBE (Reversing Gear) Powershift Unit |
| Series | WG 180 |
| Overall Length (approx.) | 420 mm |
| Dry Weight (approx.) | 38 kg |
| Housing Material | High-strength cast iron |
| Max Input Torque (est.) | 1,800 Nm |
| OEM Reference | ZF 4644.004.134 |
| Seal Type | Viton O-Ring (compatible with 0634306525) |
Compatibility
This complete assembly is engineered for the ZF WG 180 Series powershift transmissions. It is also compatible with the WG 200 and WG 150 series when used with the appropriate 4642303093 OUTPUT FLANGE adapter. The unit fits industrial loaders, forklifts, and specialized construction vehicles that require a compact reversing gear. For proper installation, ensure the 0636021010 HEXAGON SCREW set is torqued to factory specifications to prevent vibration loosening.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105413 | DISCONNECTION | Isolates driveline for service |
| 4642303093 | OUTPUT FLANGE | Connects assembly to driveshaft |
| 0636021010 | HEXAGON SCREW | Secures housing and flanges |
| 4644101222 | TRANSMISSION HOUSING | Main structural casing |
| 4644301226 | TRANSMISSION HOUSING | Alternate housing variant |
| 0730365067 | TYPE PLATE | Identification and rating label |
| 0631311009 | GROOVED STUD | Alignment and mounting pin |
| 4644301298 | COVER PLATE | Seals access opening |
| 0634306525 | O-RING | Hydraulic seal for pressure retention |
| 0636305026 | SCREW PLUG | Closes fluid ports |
