Great answer search it dont bother me with your BS right........did i already search that???? you wouldnt know right
if you did search, reading just a couple of the threads would have given you the answers. but let me go ahead and answer it again.
turning in 4wd and pop/clunk = front axle binding/disengaging
front axle binding causes are....
aftermarket suspension? top perch? water in front diff? vacuume line leak? axle broken? hub broken?
you dont specify how fast you were going, how hard you were turning, fresh snow? packed snow? (there is a difference there. i live in colorado, we have snow) uphill downhill? truck mods? if you want answers, provide specifics since you think this is different than all the other 4wd clunk/pop threads. what remedies have you tried from all the searching you have done? we will help, but need details.