Overview
The ZF 4644.105.414 DISCONNECTION is a critical hydraulic control component engineered specifically for the WG 200 series powershift transmissions. This OEM genuine part governs the precise engagement and disengagement of the clutch pack, ensuring seamless torque transfer during gear shifts. Positioned within the valve body assembly, the disconnection valve modulates oil flow to prevent clutch overlap and driveline shock. The SKU 4644.105.414 is manufactured to ZF’s original tolerances, guaranteeing direct interchangeability without adaptation. When paired with a properly sealed TRANSMISSION HOUSING, this valve maintains consistent hydraulic pressure across all operating temperatures.
Symptoms of Failure
- Delayed or harsh shifting under load: A worn 4644.105.414 disconnection valve causes sluggish gear engagement, particularly when the transmission is hot. Operators often report a “clunk” during directional changes.
- Intermittent neutral condition: If the valve spool sticks, the transmission may momentarily lose drive power, creating a dangerous “false neutral” at low speeds.
- Hydraulic oil contamination in the sump: Internal wear particles from the disconnection valve migrate into the oil circuit, accelerating damage to the OUTPUT FLANGE seal surface.
- Erratic clutch pressure readings: Diagnostic tools will show pressure fluctuations exceeding 15 psi during steady-state operation, indicating internal leakage past the valve spool.
Technical Specifications
| Part Number | 4644.105.414 |
| Material | Hardened steel spool with anodized aluminum body |
| Operating Pressure | 150-290 psi (10-20 bar) |
| Weight | 0.85 kg (1.87 lbs) |
| OEM Reference | ZF 4644.105.414 |
| Seal Type | PTFE energized lip seal |
| Temperature Range | -40°C to +120°C |
Compatibility
This disconnection valve is primarily designed for the ZF WG200 series transmissions used in mobile cranes, forklifts, and heavy-duty wheel loaders. It is also compatible with the WG180 series when used with the correct HEXAGON SCREW torque specification. The 4644.105.414 replaces earlier revisions in WG200 models produced after 2012. For dual-path applications, verify housing clearance using the TRANSMISSION HOUSING variant 4644301226. Do not use this part in WG120 or WG160 series without consulting the ZF parts catalog.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644303409 | OUTPUT FLANGE | Transfers torque from the transmission to the driveshaft |
| 0636021083 | HEXAGON SCREW | Secures valve body and housing assemblies |
| 4644101222 | TRANSMISSION HOUSING | Main structural casing for gear and valve components |
| 4644301226 | TRANSMISSION HOUSING | Alternate housing variant for WG200 dual-path models |
| 0730365067 | TYPE PLATE | Identification plate with serial number and model data |
| 0631311009 | GROOVED STUD | Alignment dowel for precision housing assembly |
| 4644301298 | COVER PLATE | Seals the valve body access port |
| 0634306525 | O-RING | Hydraulic seal between valve body and housing |
| 0636305026 | SCREW PLUG | Closes pressure test ports on the valve body |
| 4475280078 | ADAPTER | Converts port threads for alternate hydraulic fittings |
