231 + 4wd woes

[JJJZJ]

in the last 6 months, I have put a rebuilt, by myself, 231 from an 88 XJ into my 93 ZJ. It snowed for the first time this yr the other day. I put it into 4-hi on the roads and began getting really bad vibes, vibes that i dont get in 2wd. I tried it in 4-lo today and get the same vibes. I need to figure this problem out soon as im driving to denver and t-case integrity withstanding, to IL right there after. Does this sound like any of the following problems?
1.bad u-joints(autozone quality done last spring)?
2. driveshaft out of balance?
3. internal transfer case problem?

any help would be appreciated,
-Jon

 

[Cody]

Pull your front shaft and drive it around in 4wd. If it still vibes it's not the shaft.

 

[JJJZJ]

yah that was the plan for today once im outta class. I was also wondering if you could do me a huge favor and let me borrow one of your front shafts to borrow for all of 5 minutes depending on what the results of pulling the front shaft are. I could compensate with spirituous beverages

 

[Cody]

You can pull the shaft from the trail rig. It's in the driveway. i'll be at work till 8 so if you need it just drop by.

Cody

 

[JJJZJ]

muchas gracias senor