Overview
The ZF 4651.125.401 INDUCTIVE SENSOR is a critical electronic component designed exclusively for the WG 100 series transmission. This OEM genuine part monitors rotational speed and position of internal shafts, providing real-time data to the transmission control unit for precise shift timing and clutch engagement. Installed directly within the valve body or housing assembly, the sensor ensures smooth power delivery under heavy loads. The SKU 4651.125.401 is engineered to ZF’s exacting tolerances, making it a direct replacement for worn units without requiring modifications.
Symptoms of Failure
- Erratic shifting or gear hunting: A failing inductive sensor sends inconsistent signals, causing the transmission to shift unpredictably or “hunt” for gears during acceleration.
- No start or limp mode activation: When the sensor fails completely, the transmission control unit may trigger limp mode, limiting speed and preventing gear engagement.
- Incorrect speedometer readings: A worn sensor can produce false output shaft speed data, leading to inaccurate vehicle speed display or cruise control malfunction.
- Delayed engagement from park to drive: Degraded signal strength often results in a noticeable lag when shifting from neutral or park into drive, especially in cold conditions.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4651.125.401 |
| Type | Inductive Proximity Sensor |
| Housing Material | Nickel-Plated Brass |
| Thread Size | M12 x 1.5 |
| Overall Length | 45 mm |
| Operating Voltage | 10–30 V DC |
| Output Type | PNP Normally Open |
| Weight | 0.035 kg |
| OEM Reference | ZF 4651.125.401 |
Compatibility
This inductive sensor is specifically validated for the ZF WG 100 series, including models WG100, WG120, WG150, WG180, and WG200. It is also used in select WG 80 variants and certain off-highway transmission applications. Always verify your transmission’s serial number against the OEM parts list before installation. For complete assembly, pair this sensor with the 4651101007 TRANSMISSION HOUSING and the 4651301029 HOUSING to ensure proper sealing and alignment. The 0634303928 O-RING is required to prevent fluid ingress, while the 4651301024 HOUSING provides additional structural support for the sensor mount.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101007 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4651301029 | HOUSING | Secondary housing for sensor mounting |
| 0634303928 | O-RING | Seals sensor bore against oil leaks |
| 4651301024 | HOUSING | Support bracket for sensor alignment |
| 4651203002 | SCREEN SHEET | Filters debris from hydraulic circuit |
| 4651303005 | SCREEN SHEET | Secondary filtration for valve body |
| 0636101032 | CAP SCREW | Fastens housing to transmission case |
| 0630361028 | SEALING CAP | Protects unused sensor ports |
| 4475280060 | SCREW PLUG | Closes hydraulic test points |
| 0634303312 | O-RING | Seals screw plug against pressure loss |
