99 24v 4x4?
 

ive got a 99 24v 4x4 automatic and i put it in 4 high today and it made come bad clunking noises and truck bounced everytime it clunked! never had an issue before when using 4 wheel drive?

Check the U joints on your front drive shaft. I have had the centering kit on the double cardian style front drive shaft go out and cause the drive shaft to swing around wildly.

Also check the axle u-joints to f or looseness or damage.

I was thinking the same thing but I kinda ruled them out as they rotate when ever the truck is moving regardless of being in 4wheel or 2 wheel drive.

But things change when lock and torque is place on them. :w2:

I have also had something like this happen on my jeep happen when I sheered off teeth on the front spider gears. On that rig, I got very good at replacing them all the time. lol

i checked u joints. all seem to be solid. and i cant tell if the noise is coming from the transfer case or front end. leaning more torwards transfer case? does this mean i need a new transfer case?

Your CAD might not be getting full movment and the collar might be popping on the outter axle.