Anybody know how many teeth on a 4:10 gear speedometer?

Doing Fords for 45 years. '56 Customline Victoria

E.J. in Havana FL

I take it is a 56 car you are asking for?



For a 4.10 ratio the parts book says 21 teeth for std and OD transmissions if you have not changed the transmission to a later model . Part # B5A-17322-B

Green Sales has 4 of them 1-800-543-4959

I don't know price.

marv

Thanks Marvh, actually it's a '62 T-85 OD transmission. Someone, before I got the car, evidently put a 4:10 gear in the rear end. Why I can't imagine, but my speedometer is off 20 mph @ 70 mph (Reads 90 mph,GPS checked). About 10 mph off @ 50. When I put the T-85 in it I need for the speedometer to at least be close. I assume it had a 3:78 from the factory with a 3 speed.

Doing Fords for 45 years. '56 Customline Victoria

E.J. in Havana FL

With this later style transmission you will have to use the 57 and later speedometer gear. You will have to pull your speedometer gear out of your transmission. It is on the drivers side of the transmission in the tail shaft housing held in by a 1/4" bolt. You need a 7/16 wrench. The gear is held to the end of the cable by a clip ( or should be) so it will not fall into the transmission like the 56 can do. The cable housing end has a o-ring seal in the transmission so is a little stiff to pull out. Count the number of teeth your gear has. You will need a new gear with more teeth to reduce your speedometer speed indication. Also check the direction (pitch) of the teeth angle, some std transmission have an opposite pitch on the gear, depending if the gear is above or below the tailshaft. I am taking a wild guess and thinking you will need a 22 or 23 tooth gear. If you need more speed reduction you will have to buy a speed reducer.



Here is a link to a site with speedometer gears and speed reducers. Down the page is a speedometer gear calculator. Just plug your info in to get an answer.



http://www.transmissioncenter.net/speedometer_calibration_______va.htm

http://www.bgsoflex.com/speedo1.html

marv

Thanks Marv. I know I have to get another housing. I've been looking at them online. I'll call T-bird, they've been helpful in the past...

Doing Fords for 45 years. '56 Customline Victoria

E.J. in Havana FL