I am guessing it may also happen as the spin cycle is starting. When it is up to speed it appears like it is in balance. As it slows down, or speeds up, it is out of balance. Does it do it without clothes in the washer? If not then it may be a function of the clothes. Maybe overloaded or too many things like heavy towels. If the transmission disengages, how it would be a cause is puzzling. Something is out of balance which caused the drive block to get chewed up. But then my own washer may have this issue and I am not an expert.