That procedure was actually part of what they called a “rock test” at Chrysler Chelsea Proving Grounds.
I don’t recall if it was at a WOT or just a high rpm. It was done to simulate getting stuck in snow, etc. I believe it had to handle 50 cycles of reverse to drive to reverse.
....boy they must have left that test in the past with the 94ish RH trans came along. We repaired so many of those that had gotten stuck. Seems to me most of them welded the output shaft to the OD piston retainer. I was just getting into “the business” at the time and a guy I worked with was losing a check ball and drilling the separator plate. Engaged a bit harsh... but they lived.
