Rick427, I discovered this technic 30 years ago. I had just put my first powerglide in and curious to see if it would even work. Well it seemed to be doing ok so feathered the idle and the drive shaft stopped, OH $xxx, I thought broke something in the tranny and shoved it into Park. Didn't hear any strange noises, so back into gear, tapped the throttle, stop driveshaft. Been doing that since.