Help me piece this puzzle together(99 AWD Mounty, no front driveshaft)

[turboplz]

I bought this truck about a year ago for dirt cheap just because I needed something for a little while, but now I've decided I want to fix it up and keep it running to use for towing and hauling. It's a 99 AWD 5.0 Mountaineer, 160k miles and full of it's own issues. Most of these are common suspension issues which I'm tackling at the end of the month, but the one that has me the most concerned is the driveline.

When I bought the truck, I didn't do a very thorough inspection and upon looking it over really well earlier this year, I discovered there is no front driveshaft. I'm clueless about AWD or 4x4 systems, but not afraid of diving in as I have plenty of rwd and fwd encounters.

Here's my questions:
1)What is the likely reason the front shaft was removed and being the truck has been driven for at least 10k miles(Lord knows how long it was like this before) what am I going to most likely need to replace?

2)I have a hard shift issue from 2-3 occasionally and it is completely dependent on the load of the engine. Sometimes it will just skip 3rd and jump into 4th, other times it will hang in 2nd and I have to punch the gas up to about 3k rpms, let completely off the gas and it will shift hard into 3rd. I don't have any trans codes, so I'm wondering if the AWD system being out of whack might have something to do with that. I was thinking about installing a shift kit to see if that helps or cures the problem, but if it's due to the AWD, that would be a waste of money for now.

3)Occasionally when accelerating from a stop, I get a clunk in the rear end. I'm not sure if that would be trans related or not. I know the posi is still working very well as I got stuck in some mud last week and I had two nice tread marks where I was spinning the tires to get out.

I'm going to start diving into research and hopefully I can find what I need, but if anyone can help me out here along the way I would greatly appreciate it. I don't have much in the way of time between work and two very demanding little kiddos!

Jason

 

[PopRichie77]

The transfer case could be bad, reason for front drive shaft missing, or the previous owner thought he would get better gas millage by removing it, doesn't work, or the CV or universals joints were bad on the shaft and rather than fixing, he just removed it. You will have to put a shaft back in and see.
Also sounds like there are trans problems.

 

[turboplz]

I've been told that the valve body might have junk in it causing the shifting issue, does that sound feasible? Only once have I noticed a flare when going from 2nd-3rd, I keep a close count on what happens and when.

I think at this point, I will try a shift kit from transgo and see if that helps or solves it. As for the AWD components, I'll start hitting up the junk yard to find a front shaft to rebuild.