I have a '97 4.0 4x4. Im having a lot of problems with my auto hubs locking in and disconecting the 4wheele drive. It either locks in or most of the time it will lock in and slip out and start grinding when im driving. Now it wont go into 2 wheels drive or 4wheele drive. It is just stuck like half way and grinds when im driving. I just had the front end rebuilt( ball joints, u joints, tierod ends, wheels bearings, exc.) Is there anything easy I can do to fix this? Is it a known problem with these truck?