While sitting there waiting for the tow truck I ran the fault codes and found a number which indicated an incorrect gear ratio. This covered a broad number of possibilities from dirty transmission fluid or blocked passageway all the way to broken components inside the transmission. Once at the shop the mechanic had hoped to see a particular code number specifying a known control module problem but that didn’t show. When he dropped the pan from the unit he then saw a sparkling array of bronze metal glitter bits all about. He suspected the bronze bushing on the input or output shaft had pulverized. So we went with a complete rebuilt transmission of a later year where roller ball bearings replaced these bronze bushings. He also had the shop that rebuilds Mercedes Benz transmissions to install heavy duty parts and pieces inside where applicable. Knowing I live in the RV full time and use it year round “I’d feel much better sending you back out on the road with a new unit built up for heavy duty service.” I agreed with him completely.
Like with the new tires, I can now continue on with peace mind.
I really should replace those windshield wipers though.