Overview
The ZF 4644.105.420 DISCONNECTION is a critical OEM genuine component engineered specifically for the WG 200 Series transmission. This part serves as the primary hydraulic or mechanical disconnection mechanism, allowing the transmission to safely isolate power flow during neutral or service conditions. Positioned within the main valve body or clutch pack assembly, the SKU 4644.105.420 ensures precise engagement and disengagement of the drivetrain, preventing unintended torque transfer. When paired with a properly sealed 4644303056: OUTPUT FLANGE, this disconnection unit maintains system integrity under high-load industrial applications.
Symptoms of Failure
When the 4644.105.420 disconnection component begins to degrade, operators may notice specific performance issues. Common failure symptoms include:
- Delayed or incomplete gear disengagement – The transmission struggles to shift into neutral, often accompanied by grinding noises.
- Hydraulic fluid seepage – Oil leaks near the valve body or housing interface, often traced back to a worn disconnection seal.
- Intermittent power loss – The drivetrain unexpectedly disengages under load, causing sudden deceleration.
- Erratic shift patterns – The transmission hunts for gears or fails to hold a selected range due to internal pressure loss.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.105.420 |
| OEM Reference | ZF WG200 Series |
| Material | Hardened steel / Aluminum alloy |
| Weight | 1.2 kg (2.65 lbs) |
| Dimensions (L x W x H) | 145 mm x 85 mm x 55 mm |
| Operating Pressure | 12-18 bar |
| Seal Type | Nitrile rubber O-ring |
Compatibility
This disconnection unit is primarily designed for the ZF WG200 transmission family, but it also fits select models in the WG180 and WG210 series due to shared valve body architecture. It is a direct replacement for the original disconnection assembly in WG200 gearboxes used in construction, agricultural, and material handling equipment. For complete assembly, this part integrates with the 4644101232: TRANSMISSION HOUSING and the 4644301282: TRANSMISSION HOUSING, ensuring a sealed, leak-free environment. Additionally, the 4475280043: SCREW PLUG is often replaced concurrently to maintain pressure integrity.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644303056 | OUTPUT FLANGE | Transfers torque from transmission to driveshaft |
| 4644101232 | TRANSMISSION HOUSING | Encloses internal gear and clutch assemblies |
| 4644301282 | TRANSMISSION HOUSING | Secondary housing for valve body support |
| 4475280043 | SCREW PLUG | Seals hydraulic ports and prevents fluid loss |
| 0634306198 | O-RING | Provides leak-proof seal between mating surfaces |
| 0730365067 | TYPE PLATE | Identification label for transmission model |
| 4644301298 | COVER PLATE | Protects internal components from debris |
| 4644106300 | SHIFT SYSTEM | Controls gear selection and hydraulic flow |
| 4644306500 | COVER PLATE | Secondary cover for access port sealing |
| 4644159300 | SHIFT SYSTEM | Alternate shift mechanism for WG200 variants |
