Hi all! I have a 1988 dynasty Apollo with a merc 4.3 4bbl and alpha one Outdrive.
Let me start by saying I was negligent and did not change the lower unit oil last fall. This spring I did, and it was a milky color. It's since been changed. Took the boat to the lake today, and it ran ok while idling. Once we hit open water, I got in to the throttle a little and got up and purring around 50 mph. All was grand. Suddenly, I heard what sounded like a clunk (thought I snapped a belt) and then a rumbling sound ensued. Luckily, I wasn't too far from launch and made it back without issue.
This low rumble (whirring like a bad wheel bearing) was persistent, but I could get it to go away if I set the trim just right. Any movement from that sweet spot though, back it came. It would get a little louder the further down or up I adjusted the trim. Also, left and right steering increased the noise.
This happened whether in gear or not. My first instinct was a bad gimbal bearing. Given the nature of boat repair shops, I can't just 'find out what's wrong' without still forking over a good bit of labor cash. Before I take it, inthink the wife wants to know what we are getting in to, and I do too. If we figure a grand I don't want a 2000 dollar surprise.
I have read through some posts and seen that my symptoms mimic a bad gimbal in some cases, and bad u joints in others.
Any thoughts? Is this a project I can tackle myself with a decent amount of hand tools, or is this better off done at a shop?
Let me start by saying I was negligent and did not change the lower unit oil last fall. This spring I did, and it was a milky color. It's since been changed. Took the boat to the lake today, and it ran ok while idling. Once we hit open water, I got in to the throttle a little and got up and purring around 50 mph. All was grand. Suddenly, I heard what sounded like a clunk (thought I snapped a belt) and then a rumbling sound ensued. Luckily, I wasn't too far from launch and made it back without issue.
This low rumble (whirring like a bad wheel bearing) was persistent, but I could get it to go away if I set the trim just right. Any movement from that sweet spot though, back it came. It would get a little louder the further down or up I adjusted the trim. Also, left and right steering increased the noise.
This happened whether in gear or not. My first instinct was a bad gimbal bearing. Given the nature of boat repair shops, I can't just 'find out what's wrong' without still forking over a good bit of labor cash. Before I take it, inthink the wife wants to know what we are getting in to, and I do too. If we figure a grand I don't want a 2000 dollar surprise.
I have read through some posts and seen that my symptoms mimic a bad gimbal in some cases, and bad u joints in others.
Any thoughts? Is this a project I can tackle myself with a decent amount of hand tools, or is this better off done at a shop?