Hello All,

I am trying to figure out what the stock tire size is on my 62' F100 non-uni. Also, If someone knows the stock tire height or diameter. My truck is about 5mph slower than the speedo reads and I would like to speed it up on the top end.

Thanks,
Marc

 

There were, at least 4 different sized tires available, just with 15" wheels. So there's no way to know what size tires your truck originally came with, and all were bias ply tires, not radials.

The thing is, you prolly have P-Metric radials on your truck which have different dimensions than the original bias plys. The only thing you could try is to replace the speedometer DRIVEN gear at the end of the cable.

If, for example, the gear has 18 teeth and the speedo is reading 5 MPH slow, you'll need a 17 tooth gear to speed the speedo up.

If the gear is nylon, Ford has used these same 16-21 tooth gears since 1960, all are available for less than 5 bucks each. If the gear is fibre = obsolete, but some can be found NOS.

 

Thanks for that info Bill. Thats exactly how many mph my truck speedo is off. I installed 16" wheels and tires that are radial but somewhat match what was originally on these trucks. I checked the speedo out with a GPS and thats about where it sits. Right now I just drive with the speedo showing 5mph lower than the posted limit. My speedo is out of a 65 2wd truck but I dont think that should make a difference. Are these gears available from Ford?

 

Does a bear **** in the woods? Do birds fly and ducks swim? Are the original oil caps available aftermarket?

 

If you asked the rabbit that the bear wiped with he would probably tell you yes after he cleans himself.

You are right birds fly and ducks swim......but are ducks a##s water tight? Or was that frogs? Oh well they both swim in the water and thats why I dont drink the water. At least not until its been run thru the local municipality.

And yes they are available but you have to paint them and I got mine from NAPA.

Thanks Ill have to pull that gear see what she is and talk to my local Ford guy.

 

You can use this program to figure out what driven gear you need. Just fill in the blanks. You need to know what drive gear you have and the rear end ratio. You can look up your tire diameter on the internet.

Speedometer Calibration Program - Method 1