Overview
The ZF 4616.305.021 PULSE DISC is a critical speed-sensing component engineered specifically for the WG 65 Series transmission. This OEM genuine part, identified by SKU 4616.305.021, sits on the output shaft assembly and generates precise rotational signals for the transmission control unit (TCU). By reading magnetic impulses from the rotating shaft, it ensures accurate shift timing and clutch modulation. When paired with a properly sealed 4616105402: OUTPUT and a robust 4005303005: OUTPUT FLANGE, this pulse disc guarantees consistent data flow for optimal gear engagement.
Symptoms of Failure
- Erratic gear hunting or delayed shifts: A worn pulse disc sends intermittent signals, causing the TCU to misjudge vehicle speed and hunt for gears, especially under load.
- Transmission warning light with speed sensor codes: Fault codes like P0722 or P0723 often appear when the disc’s magnetic pattern degrades, triggering limp-home mode.
- Intermittent loss of cruise control: Since the pulse disc provides road speed data, failure can cause cruise control to disengage randomly at highway speeds.
- Harsh or clunking downshifts: Without accurate pulse data, the TCU applies clutches at incorrect moments, leading to jarring gear changes.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4616.305.021 |
| Material | High-grade ferromagnetic steel with nickel plating |
| Outer Diameter | 120 mm (estimated) |
| Inner Diameter | 45 mm (estimated) |
| Thickness | 8 mm (estimated) |
| Weight | 0.35 kg (estimated) |
| OEM Reference | ZF 4616.305.021 |
| Pulse Count | 48 teeth per revolution |
| Operating Temperature | -40°C to +120°C |
Compatibility
This pulse disc is a direct fit for the ZF WG 65 Series transmission family. Based on its design and mounting pattern, it is also compatible with the following ZF models that share the same output shaft architecture: WG180, WG200, WG210, and WG250. Always verify the output shaft diameter and bolt pattern before installation. The disc mounts directly behind the 4616101119: TRANSMISSION HOUSING and is secured using 0636011038: HEXAGON SCREW fasteners.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616105402 | OUTPUT | Transfers torque from planetary gears to output flange |
| 4005303005 | OUTPUT FLANGE | Connects driveshaft to transmission output |
| 4616101119 | TRANSMISSION HOUSING | Encloses gear train and supports bearing bores |
| 0636011038 | HEXAGON SCREW | Secures pulse disc to output shaft |
| 0636011118 | HEXAGON SCREW | Fastens output flange to output shaft |
| 0636016015 | HEXAGON SCREW | Mounts housing cover to main case |
| 0631306085 | CYLINDRICAL PIN | Aligns pulse disc during assembly |
| 0634313118 | O-RING | Seals pulse disc cavity against oil ingress |
| 0636304019 | SCREW PLUG | Closes sensor port in housing |
| 0634801152 | SEALING RING | Prevents fluid leaks at screw plug interface |
