I wonder if an oil analysis would catch the plastic debris in the oil. I know the excessive metal would show and figuring out where the metal was coming from without additional symptoms would be difficult.
There have been a few really bad power train failures in rigs but it's a pretty rare occurrence and usually showed up during the warranty period. Most of what you might read about concerns loss of power or general poor performance and is mostly, but not always, associated with something outside of the engine block. Fuel delivery problems, coil on plug failure or starved for air. When considering the relatively low milage an average coach might have wear failures as shown in the video are not common.
My coach, 2006 model year F53 chassis with 56,000 miles. Had two problems since 2011 when I drove it home. Power steer pump shaft seal leak and an electronic throttle servo motor failure. Both were easy driveway repairs.
