Keeping in mind the truck has 385000 on it anything that happens is expected, but had it in four wheel drive working in the ditch in some mud and went to get back on to the highway and heard a loud bang. So had a look and the chain had come of the gears in the transfer case and punched out a huge chunk of the case. Loaded it up and took it in a rebuilt one was 2300 dollars, which sucked didn't think it would be that much. But at least it runs great again.