94 B4000 4x4 Problem

I was driving on the highway going about 70 in overdrive and a whining noise, almost like I was in 4 wheel drive starting coming from the right front wheel area. I pulled over and noticed that my 4 wheel drive no longer will turn on when I press the button, and it makes the whining noise (like it's in 4 wheel) in every gear (including overdrive and reverse) except 4th. Any ideas?

Might want to check the front wheel bearings. More info in this thread:
( http://www.automotiveforums.com/vbulletin/showthread.php?p=4320688 )