Speedometer Question

The bushing on the head where the cable goes into the cluster is lacking lube. Try some 3 in one oil. Also over time the magnet in the head will loose strength causing the gauge to not read the correct speed at all or any speed. This magnet can be recharged and the speedometer calibrated to read the correct MPH at all speeds. A few unwanted speeding tickets are worth the price of having a speedometer looked at by a professional.