My son was on the water the other day when the motor reved up , but the boat came down from plane. When he came home we are able to spin the prop by hand in either direction with the shift engaged in either forward or reverse. Over lunch yesterday I removed the lower unit drain plug to check for metal and it was under alot of pressure, would this be normal? The lower unit is under warrenty and I plan to drop it over the weekend and ship it back to manuf, but am curious to what might be the problem.