Speedometer Gear Tooth Count?

banjopicker66 · Post by **banjopicker66** » April 2, 2011, 11:09 am

Anyone know what the original speedometer tooth gear count would have been for a Slick with a 3.25 rear?
I put a C-6 in it, and then changed rear gears around so I forgot what it would have been originally.

Uncle Skip · Post by **Uncle Skip** » April 2, 2011, 6:42 pm

Banjo.
I have a 3.25 posi and I "think" I used the 17 tooth in my C-6. Its been a long time, but I think I remember it being the green one.
Skipper

oldfordcoupe · Post by **oldfordcoupe** » April 3, 2011, 8:37 pm

i now have a cv rear end with a 3.27 gear an i had to go with a 20 tooth gear for the speedometer to read near right 16 an 17 gear were way to fast reading almost 20 mi hr fast

banjopicker66 · Post by **banjopicker66** » April 5, 2011, 8:35 am

Thank you gentlemen! It turns out, Skipper, that I had a 17 tooth gear in there already. Even with that, though, with the 2.75, the speedometer was reading 50 when I was doing 60.
OldFord, I put a 19 toothed gear in there per your suggestion, and it is giving me very close results. I show 36 MPH when doing 35 actual, and 47 at 45 actual.
I think the differences between the different recommendations as to which gear count to use have to do with the drive gear count on the transmission output shaft.
Thanks again.