Ya is there any way to Id you ratio, beside build sheets which I do not have right now (in progress)? I have the 2007 jeep 2-door X stick which has two choices 3.21 or 4.10.
I have searched and could not find any on this...
If not I guess I will just have to wait till I get me sheet…
Thanks guys!!

 

If you have the tow package then you will have the 4.10s, if not then you indeed could have either, as the 4.10 gear was still a $50 independent option and the 3.21 is standard. I believe you can order a build sheet through the Jeep website, or certainly your dealer should be able to do it.

You also to jack the Jeep up and do the ratio by counting the driveshaft revolutions per revolution of the tire.

 

This was posted by Ronjenx:

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 and/or 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

 

FWIW, if you're unlucky enough to have a D35 rear end in that JK and you don't have 4.10's, but want them... I've got a set of 4.10 gears for D35 that you can have for the cost of shipping + eh, $10. Let's just say $25 shipped.

 

Check out this reference:

http://www.offroaders.com/tech/jeep/...axle-guide.htm

 

Thanks for all your help guys! But if I have a Dana 44 in back that would mean I would have a 4.10 ratio right?? Because if I had the D35 I would have a 3.21 ratio right?? I looked around and I think I have a D44 in back!!! Does anyone have pics of these two...? D35 and D44 or one either one to just clarify… This would be an easier way to find out, no?? Thanks again!!!

 

No, the D35/D44 choice has no effect on the gearing. There were very few D35's that made it into the JK anyways so more than likely you have the D44 in the back.

 

Oh ok because jeeperjkj talked about the D35 on back so I started to think that maybe I could tell by that. But I guess not, oh well at least I have one good thing going for me (D44) out of the two (ratio4.10) for now! Also if I end up having the 3.21 ratio how much would it be to put in a 4.10 ratio? I heard that it was only a $50.00 option at the dealer? I don’t know why anyone would not want to upgrade ($50)??

 

isn't the ratio on the diff tag?

 

I needed to know also and I just gave my vin to the dealer and in five minutes I found its dana 35 front and dana 44 rear 3.21 gears.