We have some snow, I noticed the other day I engaged the 4WD and as I started driving I heard a clicking noise as I increased my speed, the noise appears to be coming from the front drivers side. It only does it when I have the 4WD engaged, could the transfer case be going out on me? I all of the fluids changed about 6 months ago. Thank you.

 

One of the two front wheel hubs is not fully engaging, most likely the driver's side since you hear the noise from that side.