Description
Electric tachometer / engine speed sensor for International and Mack heavy-duty trucks. PAI 450590 replaces Navistar 556915C91 (also 556915) and Mack 4333-556915C91. Two-pin oval connector with 3/4″-16 mounting thread and a 30.6″ integrated cable for routing to the dash gauge or ECM-side circuit.
Signs You Need a New Tachometer Sensor
- Dash tachometer reads zero, drops out, or fluctuates erratically
- Engine speed signal codes at the ECM
- Cruise control kicks out at random
- Visible damage to the sensor body or pigtail
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 450590 |
| Part Type | Electric Tachometer / Engine Speed Sensor |
| Pin Count | 2 |
| Connector Shape | Oval (plastic) |
| Thread Size | 3/4″-16 |
| Overall Length | 30.6 in (cable + body) |
Cross References
This tachometer sensor replaces or is equivalent to the following part numbers:
- International / Navistar: 556915C91, 556915
- Mack: 4333-556915C91
- Also known as: 5MT2033C
Applications
This sensor fits the tachometer / engine speed signal pickup on heavy-duty truck applications:
- International / Navistar conventional trucks (multiple model years using the 3/4″-16 mechanical-pickup tachometer drive)
- Mack conventionals using the 4333-556915C91 stocking number
Verify the existing sensor body, thread, and cable length against your application before ordering — mechanical and electronic tach pickups are not interchangeable.
