So i just bought this truck. Its a 97 ford f150 4.6l 4x4. I noticed driving it home that 22mph is actually 25. 31 is really 35 and so on. The truck is all stock except the tires which are 265/75/16. stock size on sticker is 235/70/16. So i went to napa and bought what i believe is a vss its in the transmission with one bolt and has a gear on the end of it. But still didnt solve the prob. I am told there is one in the rear diff on top also but its only a abs sensor? so from here im not sure what to do to fix the speedometer prob and its really bugging me. Also to the symptoms the overdrive does not work it struggles up hill and shifts at high rpm. how can i fix the speedometer problem. i hear there is no tuners for this year truck. thank you.

 

You need the right gear for your VSS.

 

ok do you know what gear i need and where i can find it at. im not good with this math stuff. thanks

 

Check your other thread.