MRP216015B The Driven Wheel shaft was worn as were the snap rings.
The "Shim" washer was missing. I am waiting for the shim washer. What is the purpose of the shim washer (29)?
The shim washer was left out by an idiot (just a guess). It is what sets the correct side clearance for the assembly to work. It prevents it from walking back and forth and slipping under load.