Magnuson-Moss act...google that shit.
Basically unless they provide wear items for free, they can't force you to do it the way they want you to.
Now if they could prove the prop was out of balance and led to the failure, thats another thing, but they'll be opening themselves up to a lawsuit if they just try to outright tell you what prop you can or can't run on their outdrive.
Thats the way i understand it anyway. They could force you to sue them though, and honestly wouldn't surprise me if thats the way it was handled, until you voiced your opinion on an open forum somewhere.

Then you'd get your service and be persuaded to retract your previous statements and shower the almighty with compliments.
