Looking at buying a 2003 Tahoe with the 4.3L Mercruiser. We had him run the boat with the muffs on & when he it put it in gear (forward or reverse) it would make a clicking almost grinding sound for a second. I asked & he stated that it has always done that. I don't know a great deal about boats but our old Mark Twain OMC didn't make a sound like that when put into gear. Is this normal for a MerCruiser outdrive