This was brought to my attention by a friend of mine that owns a Class A Thor Axis. There is a possible issue with the transmission shift cable on the Ford V-10 engines. The problem can affect both Class A and Class C Ford E350 and E450 chassis. The transmission cable passes very close - dangerously close to the exhaust manifold and exhaust pipe. The heat from the exhaust can burn the shift cable protective sheath and disable the ability to shift the transmission.
To date there is no Ford recall.
To inspect, crawl under the coach on the driver side behind the front wheel. Go to just under where the drivers seat location is. Follow the exhaust pipe to the exhaust manifold. Right the the transition from the manifold to the pipe you will see the transmission shift cable routed down from the steering column, passing the manifold going to the rear section of the transmission.
My Class C E450 is fine but I did fine my cable had popped out of the clip that holds it away from the exhaust area. I was lucky. One Thor owner was not so lucky. This is not a RV make/brand issue it is a Ford issue.
For details on the Thor owners look here: Ford shift cable failure