Axle ?
 

Hey guys, I need to replace my whole front axle. How do I check what gears I have to make sure the new junk yard one is right? Thanks

Check for an ID tag on your rear axle, it should have a series of letters and numbers like "3 55" and that will mean you have 3:55 gears, for example. That's the sure-fire way to tell, but as a rule of thumb, a 4.0 auto has 3.55s, but there are several other variations, so check the rear diff cover to be 100% sure.

X2 on what True said. You should order a build sheet to get the info that the factory has on your Jeep.

Yeah, a build sheet is def. available for your XJ, so you should order one for this and a slew of other information.

You still have the link for him True, I couldn't find mine just now?

I dont think the rear axle has the tags anymore, the front may. I dont have a lot of time to wait for a build sheet. I broke the lower control arm off the axle saturday night and am pressed for time cause its my daily driver. Would it be safe to assume that most 4.0 auto's had 3:55's?

From the factory 3:55s unless they had the towing package which was a tranny cooler and lower gears.

Call your local Jeep dealer, give them your VIN#, and they should be able to call up your build sheet right over the phone and tell you what gear set it has in it. I ASSUME you have 3.55s, but you know what happens when you assume...