speedo recalibration

[donaldderby]

any one know what id have to do to recalibrate the speedo in a 87 f250hd aftr going from 30.5" tires to 33's? any helps apprecited. thanks

 

[FreddiefiredogX4]

any one know what id have to do to recalibrate the speedo in a 87 f250hd aftr going from 30.5" tires to 33's? any helps apprecited. thanks

 

[FreddiefiredogX4]

Well, I went down to the Ford place and asked them what I could do with my 33's. They matched up the best drive gear for the speedo cable and tire size and it was still off 10% I reckon cause 82 in a 70 is expensive. I was on 75. so watch it on the road. Offroad I don't have that problem.