Bought this jeep few months ago and I will be changing the fluids this weekend. It has Rock Crusher diff covers and the dealer that took it as trade in didn't know jack about it. If I take the covers off how do I tell what gears I got? Also how do I identify the axles? Dana 30,40, ect........

Rubi?

Most likely you have a dana 30 in front and 35 in back. Depends on the model depends on the gearing. At the 9 oclock position while looking at the diff, unless they changed the gearing should say right there.

There should be a tag on the rear diff to tell you what diff you have and the gearing. Though I do know if you have a Dana 44 the drain plug is a solid metal threaded plug. The 30 and 35 have a rubber drain plug. As far as the gearing goes, if there is no tag on the diff: Jack up your jeep so both rear wheels are off the ground. Spin the rear wheel one full rotation and count the amount of times the driveshaft rotates. That is the gearing. Most Dana 44's a 3.73 or 4.10 unless re geared at some point. And the Dana 30 and 35 I'm not sure of, but probably in the 3.4 or less.

Thanks, time to tinker.

Your Bio say you have an '05 Rubi...so I'm thinking you have Dana 44's with 4.11...check the tag on the diff if the PO didn't toss it when they changed covers. Let us know what you find.

Ignore the website i got this from but look at the pics and match it up to your diffs.

Axle Identification Chart

VERY HELPFUL