This Didn't Sound Good

[BigDs_2000]

Used my 4x4 for the first time today. Got enough snow to make roads a little slick. As I was going down the hiway I heard a sound coming from the left front that sounded like a bearing going out, I guess. Took it out of 4 wheel drive and it still made the noise. Stopped and unlocked the hubs and still had the same sound. Once I did a u-turn to go back home, it quit. Had to put it back in 4x4 to make it up some hills, and no sound. Granted I was only doing a maximum of about 30mph at this time, it worked good with no unusual noise. Got any ideas? It's never made any sounds before this. But, like I said it's the first time I've used the 4x4.

2000 F-350 dually

[Zaairman]

Probably a U Joint or a hub bearing.