Home › Forum › Ask A Member › Gear lash, odd sound in Sea King 15 › Re: Gear lash, odd sound in Sea King 15
I will start by saying I have a number of 15-18hp OMCSs of 50’s and 60’s vintage. One of them is, in fact, a 1962 Sea King 15. I’m still trying to sort out an issue with mine that keeps it from pumping fuel, but that’s a different topic.
Some gear noise is normal for these motors and some make more noise than others. I do have a couple of questions about your case though.
1. Is the RPM dependent buzz / whir yours is making coming from the gearcase or possibly somewhere else? You mentioned it only does this in neutral, but the vibrations to motor makes changes a bit when in gear and under load.
2. A 1/4 turn of lash in the prop shaft when is gear sounds like normal clutch dog engagement. Meaning, if it is in gear whether forward or reverse and not running, the prop can be turned approximately 1/4 turn freely between the drive lugs of the gears.
3. Are you turning the drive shaft by hand with the lower unit removed from the midsection when you get the pronounced sound of gears engaging? These gearcases have fairly coarse gears and feeling and hearing them meshing is normal, but if it seems excessively rough or loud, there could be an issue.
4. It sounds as if the only timagine you are experiencing any gear whine is while running in neutral and it goes away once the lower unit is shifter into gear. Is this true? In my experience, the whine is usually heard while running in gear more so than the gearset being run in neutral. That almost sounds like there may some bearing wear in the gearcase which is allowing the gears to slop a bit when the clutch dog isn’t fully engaged one way or the other. The whole gearset runs all the time minus the clutch dog and the prop shaft. The clutch dog being engaged in tongue lugs of either of the spinning drive gears spins the prop. That may be taking out some of the free movement of the gears and reducing the whine when in gear? Forgive me if I ran you thru something you already know. I don’t know how familiar you are with these gearcases.
5. How.long have you had / been running this motor? It sounds like this sound is only a recent occurrence.
-Ben
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