Jason69

I recently bought a 2000 XJ with 113K at an auction. I want to eventually lift it, but it turns out it has a few issues to correct first.
1) vibrations at 60+ mph you feel it in your seat not steering. If you shift to either 4wd full or part time the vibrations reduced by 20%. If you take the front drive shaft off vibrations are gone 90% or more. I had the ujoint toward front diff replaced, left the doubble cardan joint alone and reinstalled the shaft. Vibration is same. Already balanced tires - no difference. Any ideas on what should be next?
2) transfer case (NP 242) will not shift into 4 low range. Originally all the positions were off one - 4 full time was in neutral positon and neutral was where 4 low was supposed to be. I took off the linkage ajustment cleaned it up so it would move and tried a couple adjustments. I got it to where it would grind trying to go into low but not engage. I tried shifting going slowly in drive and also tried stopped. It would also then grind trying to go back to 4 full. I would have to shut off the vehicle in (transmission neutral) then shift transfer case back to 4 full to get out of transfer case neutral. When adjusted like this it would not go into 2wd. I put it back to its original position. I have 2wd, 4 part time, 4 full and neutral, no low range.
3) transfer case makes noise at stop especially when in drive but will also make it in park sometimes. As soon as you accelerate the noise goes away until you stop again.It sounds like something rotating and hitting or rubbing into something. Like maybe the chain.
4) oil pressure seems high. It will max out at 80 when it is first started. Once it is warmed up driving and goes back to idle it will be 40-50, it is 60to 75 going down highway at 2200 rpm.

Any help is appreciated.