Overview
The ZF 4644.311.192 DRIVER is a critical actuation component engineered specifically for the WG180 and WG200 transmission series. This OEM genuine part functions as the primary interface between the hydraulic control unit and the mechanical clutch pack, translating fluid pressure into precise linear motion. Located within the valve body assembly, the DRIVER ensures smooth gear engagement and disengagement during heavy-duty operations. The SKU 4644.311.192 is manufactured to ZF’s original tolerances, guaranteeing direct fitment and long service life in demanding industrial applications.
Symptoms of Failure
- Delayed or harsh shifting: When the DRIVER wears, operators often notice a pronounced lag between gear selection and engagement, followed by a jarring shift. This symptom is frequently searched as “ZF WG180 transmission shifting delay.”
- Intermittent gear slipping under load: A failing 4644.311.192 can cause the transmission to momentarily lose power during uphill climbs or heavy hauling, a condition mechanics describe as “WG200 gear slip under torque.”
- Hydraulic fluid contamination: Worn internal seals on the DRIVER allow debris to enter the oil circuit, leading to “ZF transmission valve body debris” issues. This often accompanies visible metal particles in the transmission pan.
- Erratic neutral-to-drive engagement: Operators may experience the vehicle lurching forward or failing to engage from a standstill, a classic sign of a compromised DRIVER piston assembly.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.311.192 |
| Material | Hardened alloy steel with nitrided surface |
| Weight | 0.85 kg (1.87 lbs) |
| Overall Length | 142 mm |
| Piston Diameter | 38 mm |
| OEM Reference | ZF 4644.311.192 |
| Seal Type | PTFE lip seal (integrated) |
| Operating Pressure | 12-18 bar |
Compatibility
This DRIVER is designed exclusively for ZF’s WG180 and WG200 series powershift transmissions. It is a direct replacement in all WG180 variants (including WG180-1 through WG180-5) and WG200 models (WG200-2, WG200-3, WG200-4). The part interfaces directly with the 4644105475: DISCONNECTION mechanism and mounts to the 4644101134: TRANSMISSION HOUSING. During installation, always pair this DRIVER with a new 0636020211: HEXAGON SCREW to maintain proper clamping force. The 4642303097: OUTPUT FLANGE must be inspected for wear whenever this DRIVER is replaced, as debris from a failing unit can damage the flange splines.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105475 | DISCONNECTION | Clutch pack separation mechanism |
| 4642303097 | OUTPUT FLANGE | Torque transfer to driveshaft |
| 0636020211 | HEXAGON SCREW | Fastener for DRIVER assembly |
| 4644101134 | TRANSMISSION HOUSING | Main structural casing |
| 4644301349 | HOUSING | Valve body enclosure |
| 0730365125 | TYPE PLATE | Identification and rating label |
| 0631311009 | GROOVED STUD | Alignment and mounting pin |
| 0636305019 | SCREW PLUG | Hydraulic port sealing |
| 4644301247 | THREADED BUSH | Wear-resistant insert for housing |
| 0634303485 | O-RING | Hydraulic seal for DRIVER bore |
