The prop on my 2018 Mercury 40 hp has 3/32" of back-and-forth movement on the shaft. The thrust washer is in the correct orientation on the shaft the retaining washer is correctly placed, and the retaining nut is torqued to 55 ft lbs. All the necessary parts are in place. The prop has not hit anything. Is the prop supposed to have that much movement on the shaft? If not, what can I do to get rid of the movement? Thanks.