Hi All,

I need some help, I've been trying to figure out how to correct my speedometer.

I have a '94 GT convertible with an AODE automatic trans. Axle code is "E" which I'm fairly sure is a 3.27 LS rear end. I'm running 245/45/HR17 tires. As close as I can figure (using 2 different GPS units) my speedo is about 9-10 MPH high, if it shows 8o I'm actually going 70.

Is there a way to correct that by changing the speedo gear, or VSS or something or am I relegated to a speedo calibrator?

Thanks in advance!

 

Gears, drive and driven control speed of VSS. The drive gear is on mainshaft of transmission and driven gear is on end of VSS>

 

Would I replace one, or both? Is there a chart that shows which one would go where?

I don't have much experience with this on a Mustang, but have done this with my Jeep. There's a chart that shows gear ratio and wheel size and corresponds to a colored speedo gear.

 

your car has aftermarket gears. you need to find out what they are in order to correct the speedo

 

Late Model Restoration Supply, Mustang Unlimited, should find chart and part at their site.