4wd howling?

[Awesomeness]

I have a 2001 z71 that I bought a few months ago. I have used the 4wd a handful of times, mostly to make sure it worked before I bought it and one other time in a little snow. I recently had to drive in some snow. I put the truck in Auto 4wd and I heard some howling coming from the front of the truck that I had not heard previously. I mostly only heard it on acceleration and turning. If I remember correctly I did not hear it in 4hi. What would cause this? I am thinking about checking the fluid in the front end. I know someone in the past has been inside the rear end of the truck, judging by the gasket. The rear end isn't in the best of shape. Hopefully the front differential is not going out...

[VikingTrad3r]

surprised nobody has replied.

 

 

did u check front diff fluid? how much sludge on the plug?

 

could be carrier bearings in front diff.