98 Ranger

Spedo is 10mph high at 70. Tires are the stock size. Anyone have an Idea to the problem and repair? Any help would be appreaciated. Thanks

Did you change your gear ratio in the axles? If so, you can correct the speedo by changing the speedo gear or you can get the Superlift True Speed calibrator.

Gears have not been changed. Does the dealer have a calibrator?

'98 is calibrated electronically. I think a dealer can do it, although some of those aftermarket programmers (Hypertech, etc.) can calibrate it too.
Because the speed is read off the ABS tone ring in the rear diff, ring & pinion swaps would not affect it. But tiresize changes will.

Welcome to having a truck, with a speedometer. How did you decide its off by 10 at 70? Also why not just drive accordingly? Im willing to bet most people on this board dont have an accurate speedo, & I cant even fit in one! :flipoff2:

It will depend on your computer; mine a 98 Ranger had no options to change the tire size or axel ratio... It was close with the 34's and 4.88's, but the 36's put it off abit.

I went with a Superlift True Speed unit. I hope they have corrected the installation procedures as the wire colors were wrong... I did get it straightened out after a few "trial and errors" sessions ...

If all else fails, just find an online conversion calculator to determine your speed and write down the numbers and tape them to your dash... that's what I did :D