Speedo gears

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
I have some 3.73s sitting in my basement that I am considering installing. What is the correct speedo gear for them, and does it actually make the speedo correct, or is the speedo (and odometer) just closer but still not exactly correct?
 
it is an AOD from who knows where

all i can really say that i know for sure about it is that with the 3.27 gears i have now, and my stock speedo gear that is in there currently, my speedo and odometer are correct.
 
It will depend if you have a seven or 8 tooth drive gear. Tilt-wheel Fox AOD's had 7, and later airbag Foxes had 8 tooth drive gears.

AOD's could come from the factory with 3.27 gears, so the current set-up might be right on.

In any case you will probably want a seven tooth drive gear in there. If you have an eight, you need to pull the tailshaft on the trans to swap it.
 
If the existing gear has 19 teeth for the 3:27's you will have a 7 tooth drive gear and will only need a 21 tooth gear for the 3:73's. Speedo will be accurate. You can confirm with a GPS.