DT85 Knocking while in gear and now will only stay in forward gear

[elvis304]

I was out on my boat yesterday and it ran great all day. then on the way back to the boat launch a Knocking noise appeared. it was loud and only when in gear. I put engine in neutral and reved it up no noise. When I finaly got to the boat ramp I put the boat in neutral and it shifted itself back into forward. I then put engine in reverse and it still moved forward. At a loss on this one help!!!!

[boats.net]

Check gearcase oil for water or metal in oil, probably will need to take gearcase apart and inspect for damage.