I'm not familiar with your model of coach. Does it have leaf springs in the rear? If so, it has happened that the rear leaf springs are mounted wrong onto the rear axle, which will make the vehicle drive crooked, or 'dog track'.
A good truck or alignment shop can fix this easily.
Jim & Kate
2016 Creekside 23RKS, 2014 Ram 1500 Eco Diesel
1995 Monaco Dynasty 36', 2005 Honda Pilot