So last weekend i put my truck into 4wd, (03 Fx4) and drove for about 100 yards in 4wd. Then turned it back off. Now since ive had this truck bout 5 months now, i realized shortly after the 4x4 would NOT engage the wheels. Thinking the problem was possibly a bad shift fork in the front. Dont ask me why i put it in 4wd again the other day. I guess i was hoping for a miracle! Well anyway i DID engage that time, however since then it has developed a slight vibration/raoring sound coming front the front end. It does it between 45-65mph ONLY. Any slower or any faster it does not. I have checked everything front realated, wheel bearings, tie rods, ball joints, tires, u joints, you name it ive looked at. Which only tells me is SHOULD be in the front diff? Now ive heard from several other people that the bearing INSIDE the front end housing on the left axle is kind of a weak point. Anybody know anything about that bearing? Since then it goes into 4x4 every time. Im gonna start tearing into the front end tomorrow. Any ideas what to cheack out as well? thanks for any help!