The tachometer sensor may fail; if the tachometer needle jumps around and the transmission has harsh shifts or does not upshift, this sensor should be checked. This sensor is mounted in a cover at the front of the motor.
Average mileage: 147,500 (108,500–188,500)
Drive Trains affected: 2WD, 4WD, 7.3L V8 Diesel, Diesel
13 people reported this problem