Just bought this truck 2 weeks ago, and out of nowhere while driving in 2h heard a loud grinding noise. Now it always makes this noise in 2h. It sounds like its not disengaging from 4h, but it was never in 4h for the problem to happen. Have taken it to a few local shops, and they all agree thats what it sounds like, and also have said i need to replace the cv shafts cuz one has a ripped boot, and the Ujoints are pretty bad too. But my main questoin is, what would cause this to suddenly happen, how do i fix it??? ive read alot on the internet, and keep reading about actuators, transfer cases, and vaccuum, but dont know what to start with as im not trying to spend a ton of money....