Started driving my 72 From 7/11 the other night and speedometer started reading about 60 when I was driving about 35. I have already replaced a lot of things as a normal replacement objective. I then jumped on the Freeway and the 120 speedometer went crazy, pegging out, jumping from 80 to above 120. Pulled over and removed the speedometer cable so as not to destroy gauge. Ordered new Speedometer cable. Just another thing I wanted to replace any ways. Replaced, and did not help. Here is the funny point. My car came with a 150 speedometer gauge and when restoring it, I had a 120 that was in a little better condition and put it in. That 120 looked better but was going bad. I put the 150 back in now and works great. Also put new LED dash lights in while replacing Speedometer. Gives a great new look over the old ones.