VEHICLE HAD CAUGHT ON FIRE DUE TO GREASE IN DIFFERENTIAL THAT HAD BOILED AND RELEASED A PLUG, CAUSING EXPLOSION AND FIRE. THERE WAS A PRIMARY CONCERN OF THE LOCATION OF GAS TANK AND DIFFERENTIAL WHICH WERE CLOSE TOGETHER. PRIOR TO THIS INCIDENT, CONSUMER HAD TAKEN VEHICLE INTO DEALER 3 TIMES WITH PROBLEMS IN DRIVELINE, BUT DEALER COULDNT DETERIME CAUSE OF DEFECT. *AK