? to find gear ratio of rear end

[chaosdanno]

ok im finding out that the rear end on my truck is not origanal. how do i find out what it is, and what should it be? gear ratio that is. 1997 f350 4x4.
thanks

[kanuck15]

jack up the rear end, have someone turn the wheel one full turn, make a mark on the driveshaft and count how many times it turns, it will get you close

[BIGBILL105 45]

It may have a little tag on it that says the gear ratio on it..

[Clintd]

What kanuck said

[brittonracing]

If you look on the door tag on the drivers door from ford, a white sticker probably on the door, but maybe in the door jam, you will see where it says axle code. Probably 2 digit letters, but maybe numbers.

Got to this website and find the ID number.

What is my Ford rear end ratio, do I have positraction - Drivetrain.com

Nice website for lots of info on axles.

[tracker8wr]

if it is an after maket gear set. the ratio is stamped on the ring gear. if it is factory u can get the axle code off od it and call the dealer ship and they can tell u what was orginaly put in that axle.