does anyone out there know how to calculate the proper number of teeth for speedometer gear in a c4 transmission?

 

Terry,

If you have a speedometer gear in there now, I can tell you how to approximate the right one. First, figure out many miles per hour and which way you are off. If the speedometer reads too high, you need a gear with more teeth. If it reads too low, you need a gear with fewer teeth. Each tooth is worth about 5 MPH, so you can go from there. It is possible to have a combination for which there is no correct speedometer gear. I know this method works because I've used it several times over the years...

BTW, you can also have your speedometer re-calibrated by most any speedometer shop if it's not quite on the money.

 

Thanks Vern.

I will follow one of my sons done the highway and see how far off i am. The cable is broke and i have the floor apart to add a new shifter. Now would be a good time to fix.

Thanks again.