Calling all NP231 Guru's

I took the rig down to RRG KY for it's maiden voyage saturday. I have 140K on the clock, 40K when purchased and 100K with my wife as a daily driver ( Mall terrain Vehicle ) I did not really beat up on things too bad this weekend ran in 4lo and crawled around and never hammered the throttle at all. After a while I noticed some sort of binding type feeling in the driveline in 4wd. I thought I had a rock in the rotor at first because I thought I was hearing the locker click in and out while driving straight in 4lo. I think it may have been the xfer case though. If I put it in reverse in 4wd it would make a clunk if I then put it on 2wd It would drive fine. If I took it directly out of 4wd while it was bound up it would still feel funny. I drove it on the road at about 30mph in 2wd with it bound up and it eventually make a loud clunk and drove fine again. Does anyone know what might be the problem or how I could start diagnosing this. I put the whole rig on blocks and ran it in 4wd. When you hit the brakes you can hear some noise coming from the transfer case and it moves around more than I think it should. It seems like the front output shaft has more play in it than it once had also. I just put a SYE kit on it and nothing seemed wrong with the case when I opened it up. I have removed the front shaft because I do not want the chain moving while I am in 2wd just in case. I am guessing that the chain is shot but I could be overlooking something. I don't want to tear into the case until Ihave the parts and am ready to overhaul it if that is in fact what I need to do. Any suggestions?

Is this the first 4wd usage since installing the SYE? What brand is the SYE?

Sounds like an install problem, or a problem with the product. Buddy of mine had his SYE shipped and installed at a shop without the snapring that holds the rear output bearing in place. This caused all sorts of problems. Anything is possible.

Sounds like it's not fully shifting out of 4wd, did you check the linkage?

Did you knock the oil pickup tube off the oil pump when you installed the SYE.

Its a PORC SYE 4x4 seemed to work fine for a few hours of hard use. It shifted in and out of 4x4 just fine. I did forget to install the oil pickup tube but was able to get it into the pump with the case half installed by using some lockwire and a little magic. Thanks for the replys keep those ideas and questions comin.

I'm placing my bet on the Oil pumps not working.

Really ! ? ! ?
Meaning the Case is cooked.....
I have driven in 2wd with the SYE installed for about 600+ miles before really testing out the 4x4. 4x4 worked fine for the majority of the day during its first hard use. I think I would have had problems before now if the pump was not working. May be not . . . Definitely something to look in to. Any other ideas?