We did the same thing. 62-65 The sensor on the speed pickup is not the same. It uses a much higher number in your calibration on your Ag leader. A lot more pulses per second. Ours would not read correctly over 10-12 mph. But would work correctly up to that speed. I don't think it could count the pulses fast enough over that speed. May be Ag leader has some update for the problem but we never checked it out. If you can stay under 10 MPH while combining you should be able to get a correct reading.