I think that rgatijnet1 has hit it on the head. Looking at the Coachmen docs for that product the coach appears to have a huge slide in the rear of the coach. Take it to a weigh station that'll allow you to weigh each side of the coach and each axle along with each wheel position. Some moving and storage places Will do that. Compare your numbers to the axle ratings and the individual wheel readings to the tire ratings. Gas coaches have a longer rear overhang than DPs and folks tend to overload them in the rear. In the past, mfgrs have overloaded the rear axles too so that the coach was overweight off the assembly line. I'm not saying that this is the problem but at 22k lbs GVWR and 38ft with the same high profile as a DP, which will usually weigh in at around 30k lbs for that size it's an item you should check.
Ron