drive line noise

i have looked and looked while searching on here and can't quite find a suitable answer for my problem. i just bought an 89 4x4 5 speed manual with 114k and a 4.0. it makes a constant grinding/clicking/metal on metal/ all-around-bad noise while im driving. it's nothing to do with the engine. i don't know about the transmission because it shifts great. it rides really smooth but that noise really bothers me. do worn out u-joints make any noises like that?, because that is the first thing i am going to replace.also' is there any problems with that transmission i should be worried about? it doesn't seem like anything too bad because it drives so well. even better than the 92 automatic a used to have. any suggestions would be appreciated and i can most likely answer any of your questions in regard to this.

i recently bought a 90 4x4 5spd and it made noises like that when driving too. turned out to be the u-joints on my drive axle. does it make the noise when coasting in nuetral? if it does then its probably the u-joints. id crawl underneath and check for play in them(the one on mine moved around about 1/4"). if it only happens when in gear, it might be something else. maybe rear diff, or transfer case. check all your fluids, and change them if you can(i dont think the tranny, tc, diffs or coolant had ever been changed in mine).....my dads truck had low transfer case fuild and started making grinding noises.

thanks man. thats kinda what i figured. im changing the u-joints on the rear driveshaft tomorrow. whats up with the reputation on that transmission though?

im not too sure. i believe about halfway through 89 they changed from peugeot BA-10 to the AX-15, ive got an AX-15 and have no issues with it and from what i read it seems like a solid tranny(i guess it would be, jeep used them for 10 years). but if you have a peugeot i cant be of much help, ive never driven one.......maybe do a search.