Originally Posted by roguejk

i have a 07 x 2dr and i believe i have 3:21
but will check using your method.

Originally Posted by ronjenx

If you bought it used, you don't know if it has been regeared, so the build sheet and VIN search may not be correct.

If you want to know for sure, and remove all doubt, do this:

Chock the front tires, fore and aft.
Put the transmission in neutral.
Emergency brake off.
Jack the left rear tire off the ground.
Put a jack stand under the frame, just in case the jack fails (had to add this).
Put an index mark on the aft end of the drive shaft, visible from the left rear wheel.
Put an index mark on the left rear tire at the 6 o'clock position.
Rotate the left rear tire 2 complete revolutions while counting how many times the index mark on the drive shaft passes its original position.
That number will be your axle ratio.
Remove jackstand and lower jack.
Put transmission in gear or Park, apply emergency brake.
Remove chocks.
If you have limited slip, jack up both rear wheels and rotate one revolution, making sure both tires rotate equally.

If the driveshaft rotated almost 3 1/4 turns, you have 3.21
If the driveshaft rotated almost 3 3/4 turns, you have 3.73
If the driveshaft rotated a little over 4 turns, you have 4.10

Originally Posted by RRCP08JK

2 revolutions? I was under the impression it would be one complete turn at the wheel? What am I missing here?

Originally Posted by fish

i had an 07 x unlimited with the tow package from the factory and it had 4.10's in it . i guess they put those in when they do the tow package upgrade