bluemistro

I recently purchased a 96 GT. The speedometer is off by about 10 mph at highway speed and by about 5mph at slower speed. I suspect that the gearing has been changed from stock. If so, how do I check for sure and how do I correct the speedo.

2001SilverGT

get a chip to re-calibrate *correct* your speedometer .. could happen after changing the stock gears ..

w11988

One way to check your gears is to raise the rear end, craw under the car and rotate the drive shaft. Note the position of the tire and the drive shaft. If it takes you about 3 1/4 turns of the drive shaft to rotate the tire 1 turn, you are probably stock. 3 1/2 turns would be 3.55, 3 3/4 turns would be 3.73, and just over 4 turns would be 4.10's.

Warprunner

What I did when I changed gears is got out my Microtuner. Let me warn you it's expensive and alot of the guys and gals in here don't appreciate the, tuner. But in 10 minutes of pressing a couple of button, my speedo was dead on. It does alot more than this and here is the link to read about it.
SuperChips

I could have sworn somewhere that changing something quickly and inexpensively would do it, but I can't find the post. Maybe wait and don't run out and buy this tuner. Lets see what the others say.

Casper98GT

If any of you guys read his message, he wrote he has a 96 GT.. Not 99+ with electronic clusters. He cant tune nothing. I bought White faced gauges and forgot to put the needles back where they came from and i was screwed for a few days until i could get back to work and hook up the WDS. If youre speedo is off, it could be the way it came. Or maybe you do have gears. If you know anyone at a FORD garage, ask him to hook up the WDS and go under VSS pids and see what that tells you. Then just adjust youre needle on the cluster. thats what i had to do.

04ShakinSteed

Use the gear calculator posted at the top of the general tech page.