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: 141,206 (100,230–167,000)
Drive Trains affected: 2WD, 7.3L V8 Diesel, Automatic Transmission, Diesel
9 people reported this problem