Overview
The ZF 4644.105.203 DISCONNECTION is a critical OEM genuine component engineered specifically for the WG 200 series transmission. This part, identified by SKU 4644.105.203, serves as the primary mechanical interface that isolates the torque converter from the drivetrain during neutral or park conditions. Positioned within the rear section of the transmission housing, it directly interacts with the 4644105417: DISCONNECTION assembly to ensure precise engagement and disengagement of power flow. Without this component, the transmission cannot safely decouple engine torque, making it essential for both operational safety and component longevity.
Symptoms of Failure
- Delayed or harsh engagement when shifting from neutral to drive — A worn 4644.105.203 disconnection unit causes noticeable lag or a jarring clunk as the transmission attempts to re-engage power flow.
- Intermittent loss of drive power under load — When the disconnection mechanism fails, the transmission may slip out of gear during acceleration, particularly in heavy-duty applications.
- Transmission fluid contamination with metallic debris — Internal wear of the disconnection splines or clutch surfaces produces fine metal particles visible in the oil pan or filter.
- Unusual whining or grinding noise from the bell housing area — A failing disconnection bearing or misaligned shaft creates audible distress that worsens with RPM changes.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 4644.105.203 |
| OEM Reference | ZF 4644.105.203 (Genuine) |
| Material | Case-hardened steel with anti-corrosion coating |
| Weight | 2.8 kg (6.2 lbs) |
| Outer Diameter | 185 mm |
| Inner Spline Diameter | 42 mm |
| Operating Temperature Range | -40°C to +120°C |
| Torque Capacity | 2,200 Nm |
Compatibility
This OEM disconnection part is designed for the ZF WG 200 series, but it also fits select models in the WG 180 and WG 190 families due to shared spline geometry and housing dimensions. It is directly compatible with the 4644303547: OUTPUT FLANGE and the 4644303012: OUTPUT FLANGE, both of which mount to the same output shaft. Additionally, the 4644101121: TRANSMISSION HOUSING provides the structural enclosure for this assembly. Always verify your transmission serial number against ZF’s compatibility chart before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105417 | DISCONNECTION | Primary disconnection assembly for torque converter isolation |
| 4644303547 | OUTPUT FLANGE | Connects transmission output to driveshaft |
| 4644303012 | OUTPUT FLANGE | Alternate output flange for different yoke configurations |
| 4644101121 | TRANSMISSION HOUSING | Main structural casing for the transmission |
| 4644301240 | TRANSMISSION HOUSING | Rear housing section for WG200 series |
| 0730365067 | TYPE PLATE | Identification plate with transmission serial number |
| 0631311009 | GROOVED STUD | Fastener for securing housing components |
| 4644301286 | COVER PLATE | Seals the disconnection access port |
| 4644301242 | COVER SHEET | Protective sheet over internal components |
| 0636101026 | CAP SCREW | High-strength bolt for flange attachment |
