I have a 1987 boat with an OMC outdrive. I took it out for the first run earlier this year and noticed a knocking sound coming from the outdrive. The knocking sound is not present or is very quiet when the boat is not in gear. When the boat is in forward there is a rhythmic knocking that increases as the throttle is increased. It seems to get louder when the outdrive is turned right or left. I don't notice the knocking in neutral or reverse. I checked the oil level in the drive and the adjustment of my shift cable and took it out again yesterday. The knocking is still there. I pulled the outdrive this morning and checked the gimbal bearing and u-joints. There is no sign of water in the upper bellows, the gimbal bearing moves smoothly and has no indication of water damage or wear and the u-joints look clean and almost new. I took the upper cover off the outdrive and inspected the gearset in the upper portion of the drive. The oil is clean and the gears look very good. I couldn't see any signs of wear or damage. What am I missing?
Thanks for your help!
Thanks for your help!