2008 FORD E-450 Wheels Problems

PURCHASED THIS MOTOR-HOME NEW IN 2009. DROVE THE MOTOR-HOME 4 YEARS APPROXIMATELY 25,000 MILES WITH NO PROBLEMS. IN MAY OF 2013, I PURCHASED 6 DELTA ESSENTIAL TIRES ( LT225/75R16 ) TO REPLACE THE OLD TIRES THAT WOULD NOT PASS STATE INSPECTION DUE TO CRACKS IN THE SIDE WALLS. THEN WE TOOK A 7500 MILE TRIP ACROSS THE COUNTRY AND BACK WITHOUT INCIDENT. WHEN WE RETURNED HOME UPON ROUTINE INSPECTION OF MY TIRES I FOUND A BUBBLE ON THE INSIDE SIDEWALL OF A REAR PASSENGER INSIDE DUAL TIRE. THE TIRE DEALER REPLACED THAT TIRE AT NO COST. ABOUT TWO MONTH LATER 10/09/2013, WE LEFT ON A TRIP TO DISNEY IN FLORIDA. ON 10/10/2013 WHILE ON I-95 SOUTH BOUND NEAR MIDWAY, GA. THE DRIVER'S SIDE OUTSIDE REAR DUAL TREAD SEPARATED AND THE TIRE BLEW OUT RESULTING IN DAMAGE TO 2 COMPARTMENTS ON THE DRIVERS SIDE. WE HAD THE TIRE REPLACED BY ROADSIDE...