Component Testing: Speedometer

NOTE: Tire size, wear and incorrect inflation can affect speedometer reading and odometer measurement.

If a speedometer tester is used, follow manufacturer's procedures. Otherwise, using available resources, allowable tolerance is one MPH for every 10 MPH actual speed.
If speedometer is inoperative or indicator fluctuates excessively, remove speedometer cable for inspection. If cable is functional with no signs of wear or damage, replace speedometer.