I just bought a 1997 F-150. It is 2-wheel drive, reg. cab, long bed. It has a 4.6L V-8 with 4-speed automatic transmission. Can the speedometer be corrected by just replacing a gear somewhere? For instance, if I change tire size or gear ratio, I will need to correct my speedometer reading. Any help will be greatly appreciated. Thank you.

 

I'm attempting to calibrate the speedometer on my 99 F150, same engine and trans as yours. I bought a Truspeed calibration box made by Superlift. I got it from 4wheel parts wholesalers. I'm also having trouble installing it and have posted a message on this board looking for help. Hope the info helps.

 

Do you guys have mechanical or electronic odometer/speedometers? I know Ford used the electronic units in the early 90s and at some point switched back to mechanical drives. If your odometer is mechanical then you correct by changing the plastic driven gear at the end of the cable. If it is electronic, you correct it by reprogramming. There is a tech article on this subject in that section of this board. Either way you neither need nor want Superlift's aftermarket gizmo.

 

All '92-up F-series speedos are electronic. They run off the ABS sensor in the rear axle. Yours ('97-up) is calibrated thru the EEC by using an OBD-II scanner.