Ian:

The older mechanical odometers will run backwards. An old used car lot trick was to hook an electric drill to an old piece of cable core and remove some of the mileage from the odometer. The new electric odometers read "forward" regardless of direction of rotation as they read magnetic pulses.

John - "The Hoosier Hurricane"

I thought most old cars had optimistic speedos. Mine reads about 8% high against a GPS. I didn't think odometers could run backwards. Easy test, drive backwards for a couple of hundred feet and see if it moves.

I need one too since I put a T-85 overdrive in my '56. Tee-bird products has some I think. I got my cable & housing there. I'm going to try a 23. Mine is 10 mph off. If you google "speedometer gear" there are dozens of places that come up....


Doing Fords for 45 years. '56 Customline Victoria

E.J. in Havana FL

Because on an inaccurate speedo in my 64 Fairlane and 56 Bird, I experimented with different driven gears using my GPS. Each tooth difference accounts for about 5 MPH at around 60MPH.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

The other possibility, that nobody knows about, would be to run the odometer back wards with a drill. I would never do that but I heard it could be done.

Frank/Rebop

Bristol, In ( by Elkhart) 

Your mileage accumulation could be reduced if somehow your speedometer cable came unhooked for a while. I didn't say that!

John - "The Hoosier Hurricane"

Skygazer...Just got back to the post. My speedo reads fast, at least 5% Ihave a 3.31 gear and guessed the speedo gear was off. Going to buy a22 tooth the next time I order from a Catalogue Co. I would like it to run slow since I have yearly "restriction" on my Classic Car insuance.. Thanks for you info.............

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Another source of the driven gears (the ones on the cable) is AutoKrafters www.autokrafters.com or 1-800-228-7346 or Dearborn Classics www.dearbornclassics.com. 1-800-252-7427. Dearborn has both left and right tilt.

Another source is ebay - put in Ford speedometer gear. That is where I got mine.

To distinguish right or left tile, look at the gear - if the top is to the right its a right tilt, vice versa left tilt.

Added 3/1 - The above is true if you look at the gear in a vertical position. However, it is opposite hat if you look at it in a horizontal position - so now I don't know which way they distinguish left and right.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

The t-bird 150mph speedometers are famously optimistic. My stock '55 bird (stock FoM, 3:31 rear) indicated about 20% high, compared to GPS/iPhone. When my speedo cable gear broke, I replaced it with a 22 tooth. Now it reads just a little higher than GPS, within normally acceptable tolerance.

Concours Parts lists speedo gears in their catalog. A little confusing 3:31 gear 19 teeth, then 3:92 gear with OD trans 20 teeth , followed with a 22 teeth 312 T-85 o.d. 3:92 .......All around $22 ...Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.