Overview
The ZF 4644.006.108 6 WG 180(500) Powershift Transmission Assembly is a complete, factory-grade unit designed for heavy-duty off-highway machinery. This assembly serves as the central power distribution hub within the WG 180 series, managing torque flow from the engine to the driveline. The SKU 4644.006.108 denotes a fully assembled unit, integrating the planetary gear sets, clutch packs, and hydraulic control valves necessary for seamless directional shifts. It sits directly between the engine bell housing and the output driveline, making it the core component for vehicles like loaders, graders, and dump trucks requiring robust power management.
Symptoms of Failure
- Delayed or harsh engagement when shifting from forward to reverse: A worn clutch pack or degraded seals inside the 4644.006.108 assembly cause sluggish response, often accompanied by a loud clunk. This is a common long-tail search query for “ZF WG180 transmission shifting hard.”
- Transmission fluid leaks around the housing mating surfaces: Cracks or warpage in the assembly lead to oil seepage, particularly near the TRANSMISSION HOUSING. Look for puddles under the vehicle after extended operation.
- Loss of power under load or gear slipping: Internal hydraulic pressure drops due to worn valve bodies or damaged O-RING seals, causing the transmission to slip out of gear on inclines.
- Unusual whining or grinding noises from the transmission center: Bearing failure or debris contamination within the assembly generates high-pitched sounds, worsening with RPM increase.
Technical Specifications
| Parameter | Value |
|---|---|
| Assembly Weight | ~185 kg (408 lbs) |
| Overall Length | 720 mm |
| Overall Width | 480 mm |
| Overall Height | 510 mm |
| Housing Material | Cast Iron (GGG-40) |
| OEM Reference | ZF 4644.006.108 |
| Max Input Torque | 500 Nm |
| Fluid Capacity | ~12 liters |
Compatibility
This complete unit is engineered for the ZF WG 180 series, specifically the 6 WG 180(500) variant. It is also backward-compatible with earlier WG 180 models and forward-compatible with select WG 200 series transmissions that share the same bell housing pattern. The assembly integrates directly with the OUTPUT FLANGE for driveline connection and requires the DISCONNECTION mechanism for clutch release. Secure mounting is achieved using the HEXAGON SCREW kit. Always verify your transmission serial number before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105475 | DISCONNECTION | Clutch release mechanism for gear disengagement |
| 4642303097 | OUTPUT FLANGE | Connects transmission output to driveshaft |
| 0636020211 | HEXAGON SCREW | Fastener for housing and flange assembly |
| 4644101134 | TRANSMISSION HOUSING | Main structural casing for internal components |
| 4644301349 | HOUSING | Secondary cover for valve body access |
| 0730365125 | TYPE PLATE | Identification plate with serial number |
| 0631311009 | GROOVED STUD | Alignment pin for housing positioning |
| 0636305019 | SCREW PLUG | Seals fluid drain and fill ports |
| 4644301247 | THREADED BUSH | Reinforced insert for high-torque fasteners |
| 0634303485 | O-RING | Hydraulic seal preventing fluid leaks |
