Actually, every time the shaft turns the hose is torqued because the interface between the packing and the shaft is not friction free. It is especially bad when shifting from forward to reverse quickly and repeatedly. This constant twisting, albeit a small amount and age cause the hoses to fail. Hose failure is kind of a big problem.If the motor & shaft are in alignment the hose pretty much just sits there holding water outside the hull. If something causes the shaft to wobble the hose will start to get a work out and water will try to enter the boat. Then it is only a matter of time.