finding gear ratios

Ok, I know this is a stupid question but here it is anyway! I am trying to figure out what gears are in my 88 YJ. I know the stock ratio is 3.07 but I don't know if the previous owner changed gears. I found a method online that says to turn the rear drive shaft and count the shaft revolutions compared to the revolutions of the wheel. Problem is that when I do that the drive shaft turns approx. 1.7 times for one complete revolution of the wheel. From the charts that I have seen that doesn't add up. I am sure I am probably doing something incorrectly but I can't figure it out. Any help would be appreciated. Thanks, Tom.

when you spin the rear tire is one or both tires off the ground? I believe you have to have just one tire up.

The whole Jeep is off the ground. I have all the tires off and the Jeep is up on 4 jack stands as I am in the process of putting a 4" suspension lift and a 1" body lift on. If it is true that one wheel has to be on the ground I guess I will have to wait until I am finished with the lifts.

Make sure you have the right size tires 217 size tire, if you have bigger tires it will through out your count too.

Yeah if you spin one side and both wheels are off the ground then the pinion yoke will spin but so will the opposite tire but in the opposite direction if unlocked. That will throw off the count.

FallstonYJ wrote:

I found a method online that says to turn the rear drive shaft and count the shaft revolutions compared to the revolutions of the wheel. Problem is that when I do that the drive shaft turns approx. 1.7 times for one complete revolution of the wheel. From the charts that I have seen that doesn't add up. I am sure I am probably doing something incorrectly but I can't figure it out. Any help would be appreciated. Thanks, Tom.

with a open rear you just doubble what you turned and it will give the 3:07 your looking for. if you want to know fro sure pull the diff cover and count the teeth or watch the ring gear go around once with the number of turns of the drive shaft.