Did you try to set it to 2HI when shut off and see what happens? When I was having similar issues a few years ago, that always got me back to 2HI.
I can see one of two things, either the encoder motor is bad (which was my issue a few years ago), or you simply need to change your transfer case fluid. I'll save the rest for Roadie to comment on. He can tell you a whole lot more than I can about this.
I can see one of two things, either the encoder motor is bad (which was my issue a few years ago), or you simply need to change your transfer case fluid. I'll save the rest for Roadie to comment on. He can tell you a whole lot more than I can about this.