Nasty sounds when in 4wd

Hi, I'm new to these boards. I did the usual search but didn't find the answers I was looking for. I have an 86 XJ 2.5ltr Chrysler 904 NP207 Warn Black Diamond 3" lift. Here's my problem, when I put it in 4wd (and only in 4wd) and move fwd or reverse I get a real nasty popping/crunching sound from under the truck. I put the truck on jackstands and put it in gear to try to hear exactly where it's coming from but can't really tell if it's the case or front axle too much metal to carry noise thru. While it was off the ground I noticed that the right front was spinning but the left front was not spinning like the otherside was. I replaced the spider gears in the front diff and it took away the play in the diff but the noise is still there, and while it was out I checked the axle ends and none of them were stripped or twisted. I don't know if taking out the front driveshaft will narrow down the problem because there would be no load being put on the t-case to cause the noise. If it does come down to being the t-case what can I put in it's place (NP231 ? ) that's stronger and wont need new driveshafts made? Holidays are coming and don't have the extra $$$$ for a total rebuild / mods. Thanks for all your help!

had the same problem. never quite narrowed it down but i did have a frozen ujoint on the front driveshaft.

check u-jopints on front drive shaft

Since your vehicle is a 86, do you have the CV type or double carden front driveshaft.

Either way, check to make sure they are greased as mine popped and groaned like yours and it was that my front drive shaft bearing were dry. I greased them well and it stopped, but eventually replaced the CV type with a double carden.

It has a cv joint up at the t-case and a u-joint at the axle. What year/model has a double carden joint that I can pull from to try it out.