All ActivityMost RecentMost LikesSolutionsTire replacement by age.I was doing general maintenance on my coach in preparation for a trip through the Midwest. I checked the tires and found that the DOT date on the outside rear duel was 2305 ( over 8 years old ) . I looked more closely and found a small amount of checking in the sidewall. Not too bad but I still had doubts about using a tire past the 7 year age mark. It was big hit to the pocketbook to buy four 22.5 tires ( only needed four as I replaced the two on the steer axle in 2011) . When the outer duel was pulled the inside duel sidewall had a huge split almost completely through the sidewall. The tread looked like brand new. My point is that looks can be deceiving, change your rigs tires by age as recommended by the manufacture. It was tempting to let them slide, I'm so glad I didn't!