My speedometer has been inaccurate since I bought my 62 Country Sedan less than a year ago. It quickly goes to 20 miles an hour when I am only doing 10 mph. The faster I go, the further it gets off. By the time I am doing 70 mph, the speedometer is showing 90 mph. Today I replaced the speedometer with an NOS speedometer and it is still doing the exact same thing. So now I am looking at the speedometer gear in the transmission. I don't know much about them. I remember that they are color coded. How do I know which one I need? My wagon has a 292 with a 2 speed fordomatic transmission and a 3.56 rear end and it came with these from the factory. I'm guessing that maybe the transmission was replaced at some time in the car's life and the new one had a different gear for a car with a different rear end, so that is why I'm now going that route.