Funny clanging and loud thunk?

Hey everyone. I just scored a 98 se 4x4 4.0 with 98k for 500 bucks. I went thru it and replaced wp, rad, hoses, brakes, tires etc. Everything is working perfect, except a loud clunk when I put it in gear and a clanging noise at low speed while coasting. I checked all fluids when I got it except the transfer case.

I pt it on jack stands and there is some slop in the rear end, none in the u joints. but when I rotate the front driveshaft there is a really clinky clunky noise.

So it up on stands now in the driveway, what is the best way to determine the exact problem. What would you do at this point?

Im going to check the fluid now and hope there is not shavings in there, I will check back in a few and report on that.

Thanks in advance

I removed the fill plug, then the drain. All of the air drained out and 2 drips of gunk. I only have about 50 miles on it after pulling it from the weeds. I'm gonna just refill it and hope for the best. While I look for a new tcase. There were no shavings, so thats good.

What do you think?

Its quiet and shifts fine now. Clunk is comming from the rear diff. So a funny clanging sound while coasting is no fluid in the tcase. Lesson learned.