Front wear happens. Checking the fluid level in the transmission, as the poster above mentioned is fine, but won't help this!!!
First, I'd check and/or change the fluid in the front axle. That is a separate reservoir and should have been changed every 100 hours or so. While sudt is OK for that front axle, a good gear lube fluid such as semi-synthetic 75w-90 would be better. 2 quarts of gear lube would only set you back $10.
That said, once things start clicking, clunking, and crunching, it is beyond a fluid issue. It's time to locate a good shop manual for the front axle and do some serious disassembling and inspecting for mechanical failures. Waiting usually just causes even more destruction. Track down the specific location of the noise.
Front drive wear failures are typically caused by poor maintenance, driving in 4WD on hard pavement, heavy FEL work, and good old fashioned father time.