Is it the Transfer Case? Please help!
 

Well it started snowing. So to get out of my driveway today I locked my hubs and tried putting it in 4x4. However, when I did, I hear almost as if a tin can is bouncing around on the passenger side. I thought it might be the CV joint popped. But it is still intact. I also noticed It does it while the hubs are locked only. After I manually unlock them no more sound. When I put it in 4x4 again same sound as if a tin can is bouncing around. Then the green light with the 4x4 sign blinks in and out. I'm thinking it's the transfer case and dreading it. That is an expensive replacement. Could it be out of fluid? Is the damage already done? It doesn't sound like grinding and there is no vibration in steering or in the vehicle at all. Just the noise.

I drive a 98 Nissan Frontier XE 4 cyl 2.4 lit extended cap 4x4

Oh god, sad to say but looks like i will be having the same faith. I am also experiencing that kind of problem with my titan. my mechanic told me to change everything (the whole part) from t-case to transfer case switch and also the wirings. is that really necessary? or they are just trying to get every penny from my pocket.

seem to be I have different faith... everything is doing fine on the part, please update us if ever those things happen to us we'll know what to do :)