ON SAT OCT 1ST 2011 I WAS TRAVELING EAST ON THE INTERSTATE AT ABOUT 75 MPH WHEN ALL OF A SUDDEN IT FELT LIKE I HAD BLOWN A TIRE. THE STEERING BECAME RATHER SLUGGISH AND I PULLED OVER TO THE SIDE OF THE ROAD. I GOT OUT CHECKED ALL THE TIRES AND THEY ALL LOOKED OK, SO I GOT BACK IN THE VEHICLE. MY GRANDSON AND HIS FRIEND WERE IN THE BACK SEAT IT WAS A CREW CAB. I NOTICED THAT THE 4WD INDICATOR ON THE DASH WAS ON BUT I HAD NOT SWITCHED IT FROM 2WD IT HAD DONE IT ON IT'S OWN . I TRIED TO SWITCH IT BACK INTO 2WD BUT UPON MOVING THE VEHICLE IT STILL FELT LIKE IT WAS IN 4WD. I DECIDED TO GET THE VEHICLE OFF THE FREEWAY SO I COULD GO SLOWER AND GET THE VEHICLE HOME, SO I EXITED THE FWY ABOUT A MILE LATER AND GOT ON THE OLD HWY WHERE I COULD GO 35 MPH. MY DAUGHTER WAS BEHIND ME IN HER CAR. ABOUT 5 MILES DOWN THE ROAD MY DAUGHTER STARTS FLASHING HER LIGHTS SO I PULLED OVER AND SHE CAME RUNNING UP AND TOLD ME MY VEHICLE WAS ON FIRE , I ORDERED MY GRANDSON AND HIS FRIEND OUT OF THE TRUCK WE LEFT IMMEDIATELY , AND BACKED OFF ABOUT 200 FEET, YOU COULD SEE SMOKE COMING FROM UNDER THE VEHICLE AND FIRE DRIPPING FROM JUST ABOVE THE TRANSFER CASE BELOW THE FRONT PASSENGERS FLOORBOARD AREA. THE FIRE SPREAD AND THE VEHICLE BECAME FULLY ENGULFED THE TIRE MELTED THE LEATHER INTERIOR WAS COMPLETELY VAPORIZED NEEDLESS TO SAY IT WAS A TOTAL LOSS. MY THEORY IS THAT THE SWITCHING MECHANISM FOR THE TRANSFER CASE IS DEFECTIVE IT SHOULD NOT HAVE SWITCHED ON IT'S OWN AT 75MPH. I ALMOST LOST CONTROL OF THE