Driveshaft noise...No vibs

Hello on my way to school one day I heard a noise coming from the front that sounded like if something was loose. As I was about to pull over it stopped. Long story short this noise only starts when I get above 15mph or so and is constant for a couple minutes then stops (no vibs). The noise only appears when the Jeep has been sitting for awhile. If I drive for 10 minutes or so then turn it off and start it back up in a couple minutes the noise isn't there. Seems to only appear when the Jeep is cold..

When I finally got some free time I decided to take a look at the wheel bearings (Jeep has 208K miles with 31's) figured they would be shot. I replaced them and noticed my axle U joints were bad so I replaced them as well. After finishing I did a test drive and the noise was still there.

Today I disconnected the front Drive shaft the noise did go away, but the U joints and the drive shaft are in good condition. Would the noise be something from the internals of the drive shaft? Should I get it balanced or just find a new one? I would like to have the drive shaft back in as soon as possible. Jeep doesn't seem right without 4wd...

It's a 2000 Jeep Cherokee with a 6.5" inch lift and NP231 transfer case.

How the front pinion look/feel? Any play in that?

Need alot more info,youve got a LP D30!Are you running DP's or LA's?Whats your castor?

I looked at the front pinion and it looks good and doesn't have any play in it. Turns a slight little before it stops which seems normal.

I assume that LA's is long arms and I'm not running any long arms. I'm not sure what DP's are tho...I have BDS adjustable control arms and after I installed the lift I had the front end aligned and they adjusted the control arms to what they needed to be. The tires have been wearing evenly and I'm not sure what my castor angle is.

I've never heard of anyone doing anything to the front driveshaft after installing a lift. I figured the slip yoke would do fine seeing as it can go in and out as needed. Is it possible to rebalance a front driveshaft?

balancing the d-shaft wont do anything. thatll cause constant vibration. do all the joints in the d-shaft seem good? not stiff or binding? what about your t-case? you might try spinning the front yoke and see if you can feel anything. also changing the fluid if it hasnt been done in a while.

They all seem good and feel good. I don't see how that's possible seeing as the Jeep has 208k miles on it. When I spun the transfer case I did hear a noise that seems like it could be the noise I hear if it was constantly spinning fast with the drive shaft in. But wouldn't that noise still happen if the drive shaft isn't in since it still spins??

only if you have an np 242. np231 it would not spin. you could try driving around again without the driveshaft in and putting it in 4wd. if the noise starts def. in the t-case.

I just tried that and I didn't hear a noise. I replaced the fluid in my T case less than a year ago after I took my Jeep in some marsh mud. This leaves me with the drive shaft. Maybe Ill borrow my brothers off his Jeep and see if theirs a noise.