You'll have to pull the front diff down and apart then. 6 bolts for each axle flange, and (4) 21mm (l think thats the size, been awhile) nuts that hold the diff to the fram. 1 wire harness connector for you actuator.
After that, you can inspect the axle in question. If it's loose and can be removed by hand, try pushing it back in and see if you feel resistance. There is a retaining ring in the aluminum housing that holds the splined shaft in. You need a rubber mallet to remove or reinstall to get past that clip. I have heard of the clips getting packed full of metal shavings and NOT wanting to release the axle shaft.
If it feels/looks like it's all the way in and you don't have that clip resistance (use the seal wear line as your guage for depth) then the case will need to be split and looked into.
If the axle DOESN'T want ro push all the way in you can tap it with a mallet to see if it will lock into place. Just beware of what I said above about metal shavings locks those clips tight.
If you pull the diff, I'd recommend draining it first to see the condition of the fluid. Thar may give you info before you dig deeper. The drain plug has a magnet on it, so wipe it on a new towel and see what's stuck to it, if anything.
