Armydad

Hi all

Is there a way to figure out what gear ratio a ring and pinion set is by looking at it? Is it stamped somewhere? Can you count gear teeth? How can I find out?

Thanks

lizzyfan

https://mustangforums.com/forum/4-6l...rs-i-have.html

MU71L4710N

almost sounds like they aren't installed in a car...

you can probably count the teeth and post asking someone to count theirs if thats the case.

Armydad

Thanks, but he is right, the gears are not in a car. I thought maybe by the num of teeth I could calculate somehow?

cliffyk

Ratios are basic 5th grade math--at least they used to be?

Anyway, the number of teeth on the ring / the number of teeth on the pinion = the ratio

for example:

a 36 tooth ring and 11 tooth pinion = 36/11 = 3.27;

41/11 = 3.73;

41/10 = 4.10;

Here's a chart of the common combinations...

BraMas

If they are OEM gears it will also be stamped on the face of the pinion gear.
Here is a pic that shows the one on the left is a 2.73 than a 3.55 and a 4.30 pinion
You can see where the 2.73 and the 3.55's say the # because they are OEM

Armydad

Thanks for the responses, I actually figured it out. I forgot about the pinion. Makes it easier to calc with 2 sets of numbers, duh.