I had that annoying sqeaky belt that everyone knows about. It was a horrible squeal that would occur during acceleration or idle. I found this article on Ford Truck Enthusiasts
about cleaning the pulleys. I had already bought a Gatorback and replaced the tensioner and idler pulleys. The noise came back after about two weeks. Got a new belt and did this and it has been quiet since early February. I'm no offroader so it doesn't see too much abuse or dirt, but I was surprised at the gunk that was in there. Just thought I'd share since it seems to be a common problem. I'll let you know if it comes back, but hopefully this will be the end of it.