newbie axle shaft help

Hey guys need some help. Im new to the XJ, bought it about 2 weeks ago. I have a 91 with the command trac. Anyways I have searched the crap out of this and really cant find a good answer to my question. I have had a clunk clunk clunk noise coming from the front pass. side wheel. It goes away when 4wd is engaged. At first I thought hub assembly or maybe a u joint but I was underneath it changing the oil. I grabbed hold of the u joint and tried to move it to see if there was any play. Well the play seems to be coming from the axle shaft where it goes into the axle. So my question is do i need a new axle shaft or what?

There's no support for the outer end of the axle shaft except for the u-joint and the hub, so if the u-joint or the wheel bearing gets loose, or if the nut on the axle shaft gets loose (a bearing killer), the axle shaft will wobble in the axle tube. It probably is nothing wrong at the inner end. If the u-joint and the bearing are good, it shouldn't wobble. You should figure this out soon, because if it wobbles enough, it might damage the inner axle seal, and that is a major PITA (remove differential, press from inside, etc.) to fix. Get under again, and see if you can determine whether the outer end of the axle shaft also wobbles. If it does, then either the nut is loose or the wheel bearing is bad, or both. If it doesn't but the inner does, you need a u-joint.

Thank you ill slide under it when I get home from work.