Howling like a wolf!

[Jimmy]

1988 11 meter has been running great! Until…. Late last season during an idle cruise, we had the Starboard drive start to howl. The howling was enough to actually feel it, and drop RPMs. Immediately put it in Neutral. Howling subsided to a very slight noise. Prop was still spinning as we were still moving with port drive. Made it back to the slip, and used the Starboard drive to dock. No issues. Rest of season to try and diagnose, it never did it again. Until now. I checked:
-both drives alignment. They are good.
-Removed and verified both raw water hoses to stuffing have flow, and the offending drive does have a drip.
- fluids in trannys good
- no wiggle on strut bearings (checked each fall pull out)

I did just order a temp pointer to check stuffing boxes when we go out again. Had a boat full both times it did it, so pulling carpet, and jumping down was not possible. It seems after letting it cool ( assuming it’s a thermal issue due to after letting the drive coast, it stops howling when re-engaged)

Anyone else ever have a wolf howling at them from below? Suggestions on causes? I am already planning on re-stuffing the boxes with the Kevlar/Graphite type stuffing.

Probably also replace strut bearings at fall pull as well. Recommendations on bearings?

[prowlersfish]

Good question. And I really don't have a good answer. I have to wonder about it coming from the transmission or even the engine? If still making the noise, will it do it in reverse? When increasing rpm? When you put it in neutral, it mostly went away. What about after you shut it off?