Grinding noise when going into neutral

[UtahBoating]

Have a 5.7 merc alpha one gen 2. First 5 times out no issues. Last outing I am getting a grinding noise when I go back to neutral from forward or reverse. I can go from neutral to gear with no issues. The grinding noise sounds like a starter grinding, not the typical shifting sound. In other words it is fast and high pitched. Any ideas where to start?

 

[alldodge]

Shift interrupter switch adjustment and check your gear lube for contamination

 

[UtahBoating]

Shift interrupter switch adjustment and check your gear lube for contamination

Changing gear oil tomorrow for winterization. Will know at that point if contaminated. Thank you for the response.