So been having issues with 4x4 for a while(won't go in 4x4) Now today I left work and noticed the truck mysteriously went into 4x4 ,even without the button engaged.Made it home ,tried to disengage 4x4 but no luck .Now it won't go into any gear at all and makes a grinding noise when I put it in park.Dont think it's the transmission but not sure .Could it be a Actuator ?Transfer case ?Anything I can check before I call a garage ? Thanks for help