Purchased truck used came with new tires, unicorn creation lt265/70r-17 load range e. purchased truck 8/12/2015 , the date code on tires (2312) on all 4 tires. in less than 6000 miles 3 tires had broken steel belts. 4800 mile vacation first leg 1300 miles mostly interstate pensacola,fl to norwich,ct doing the speed limit, i have a truck camper approx. 2000 lb so i am about a 1000 lbs under max.we left norwich,ct went north up us 1 up coast of maine to fort kent then came back south down the middle of maine all back roads which were rough across new hamp. and vermont to ny . going slow [45/50] most of the time never noticed tire viberation untill got on i-84 in ny to albany. then noticed vibration.from albany,ny to scranton ,pa . vibration got worse went to tire shop in va. had front tires balanced about 50 miles down the road still vibrating found another tire shop they found right rear tire belt broken , got to macon ga. went to shop left rear tire with broken belt came on home approx 320mi and had right front tire with broken belt . so 3 out of4 tires all the same mfg date with belts breaking . ran air pressure as per door decal 75 front 80 rear. when i would get the vibration i would get off the interstate onto secondary roads to slow down and viberation would ease up.i only have one of the tires with a bad belt.