Help!! Need front drive shaft or axle??

I was on the highway and I started getting a really bad vibration, and loud clunk. I pulled over ASAP and hopped out to see what was going on. Nothing is totally f***** but Im not sure where to start, I tried searching and I think Ive narrowed it down to maybe the front drive shaft ujoints maybe a front diff? Its a 92 4 cyl 4x4, 5 speed. Not sure which t case I have. I was thinking that could be a problem. Its driectly related with speed when I let the clutch out it doesnt do anything put as soon as the speedo registers it starts to clunk . Any more than 10 mph and it is unbearable. So I limped it into a parking lot and I need to get this thing fixed. Hope somebody can help asap!!!!

Just wanted to add It seemed as though the front drivers side wheel was buckling. Maybe wheel bearing???? Im going to jack it up and spin the wheels, shafts etc. and track this down. Id really appreciate any suggestions thanks guys

my suggestion....get under there and grab and wiggle anything you can get your hands on. and definitely check the wheel bearings. grab the front DS and see if it is loose. check the pinion and the u joints at the top and bottom of the DS

Jack it up and check those wheels--grab at 6 and 12, if it wobbles the ball joints are bad; grab at 3 and 9, if it wobbles the unit bearing is bad.

Check the axle u-joints.

Pull the front driveshaft and check the u-joints. You can drive it without the front driveshaft in, see if that makes a difference.

Check the front axle pinion and yoke for odd movements.

Update... So last night by the time I got my rig home, It was about 7:30 pm maybe 15 degrees f. I did check Wheel Bearings, ball joints and trans. I rolled it down my driveway with the trans. and transfer case in neutral and it still did its clunk. I was out by myself trying to isolate the sound which really couldnt get much more difficult. So I saved the rest for today, I had to rent a car to get to work today and Im hoping to leave early to go work on the rig. My question is if the trans and transfer case are in neutral that only leaves from the t-case to the wheels, right? When everything is in neutral does the front DS still spin? Im going to pull the front DS today and see if that solves my problem. Any help is GREATLY appreciated. Thanks guys.

yes the front driveshaft always spins with the front wheels. its a good call to remove it and see if that has an effect

Ok thanks for confirming that. Im pretty sure I narrowed it down to the t-case side of the front DS. Either that u joint or yoke maybe? Ill do an update once I pull the DS.

Ok, well after my issue last week I got the flu so that was three days of puking, sleeping and trying to get stripped bolts out of my DS. Youll have to forgive me for not knowing as I dont know everything there is to know about 4x4 systems, Ive been more of a speed junkie with previous cars and quads/sleds. I finally got all the bolts and pulled the front DS and the problem was very obvious. The H piece just off the Tcase has that centering ball, that piece is all jacked up. Where and how much could I locate what I need to replace. Were expecting snow this week so Id like to be able to use 4wd with my new tires. I dont have any pics but I know somebody has run into this prob before. A little info about what I got too, its a 92 cherokee, 231 Tcase, 5 speed trans, stock axles, its got spicer DS front and rear. Any suggestions??

The piece your refering to is the double cardan joint. So i've heard those things can make one hell of a racket when the go. At this point you have a couple of options. Have a local DS shop rebuild it for about $180. Rebuild it yourself for the $80-100. Or just head down to the JY and pull one out of anoher XJ for aboyt $40. (you do run the risk of having to rebuild that one down the road or just get another when the time comes)
One link i came up with for the DIY rebuild is http://www.rblewis.net/personal/bronco/driveshaft/

Thanks for the help, Id rather spend the extra cash and have it rebuilt, just for piece of mind. And yes, it was pretty damn loud, plus i was doing 70 +/-.