loud clunk when switching out of 4x4
 

my truck makes a really loud clunk when switching out of 4x4 especially when switiching out of 4LO. anyone have any info on what this could be ?

How loud is it? Generally, you will hear a clunk when the transfer case shifts from 2WD to 4WD or vice-versa. It shouldn't be too loud, but it will be noticable.