my speedometer says 60 mph but really i'm only going 40 mph... i even drove side by side with my bro to really find out... what do you think is the problem?

 

rear gears, or overall tire diameter. you can get speedometer gears from 50resto to correct

 

thanks bro

 

Did you chang your rear gears or put different smaller sized tires on??? If you did then make sure you replace the gear with one that has the correction factor suited for whatever you are running.

 

is it 5-speed or aod ?

also what year......every store will tell you get a 23t gear, but thats not always the case....aod cars cannot be corrected past 3.55 gears, and depending the year, a 5-speed cannot be corrected past 3.73 w/ out using the non ford 23t white gear that will chew up in there.

there are 2 gears, drive and driven

if it's a 6t, then your ok 7t cannot correct for 4.10's..... 8t like in all aod's cannot be corrected past 32.7 w/ ford gear, and 3.55 w/ the white one