Drivetrain Problem??

heres the situation:
my 91 (if it matters: 8in lift, 35s etc) has been making a pinging/rattling sound when in low speed acceleration (0-30). I drove it at higher speed (40-45mph) and didnt hear the sound. sounds like its comming from the rear drive shaft area...maybe around where the driveshaft connects to the transfer case?? not sure though, and Im not sure if it is something thast would keep me from driving 6hrs back to school. please offer input!

thanks

chris

also...when if 4wd fulltime, it doesnt make the rattling sound as much..same when in 2wd 1-2gears. the sound is still there though??

Have you just checked for loose stuff? Do u have an e-brake? Is the exhaust hanger hitting the leaf spring? Just check for anything that may hit something while driving, or something that is loose. Hopefully it is nothing major...

Ive checked for loose stuff. . .it seems like it may be something loose. . .but the sound spins . . thats what makes me think its a driveshaft thing. . I havent noticed anything out of the ordinary. I mean, I cant see anything and it seems to be intermitant. like I dont know what a broken axle shaft would sound like. . .but there are no vibrations or really anyother noises that are out of the ordinary

Have you checked the u-joints yet? You probably ought to lube them anyway if you're going to be driving that far. Heck, might as well lube everything under there while you're at it.