I've noticed the last couple of days that I have a fairly loud whirring noise that seems to be coming from my tranfer case. I haven't been able to spend the time to crawl under it with a stethescope to pinpoint the source.
I don't remember hearing it until 2 days ago. I can't tell if it goes away when I put the truck in gear. I heard it when outside the truck, shutting the garage door and it was loud enough to make me look underneath.
Any ideas?

 

I had the same noise I think you are hearing.I thought it was coming from the same place you are talking about.I found out I had a plastic intercooler and it was leaking.It was replaced by the dealer with the metal one and no more problems.I hope this helps.