Trojan Boat Forum

After my rudder and prop were repaired/replaced last year when I finally discovered “the rock” after 44 years on the same lake, things were running well, but I notice a high pitched “squeal” at between 1000 and 1200 RPM, and it seems to be coming from the shaft. The shaft was measured during the repairs and was within spec and “true”, nothing off center, etc. There is none of the “squeal” above 1200 rpm. My setup is a single Chrysler Marine 318, Velvet Drive tranny, so single shaft spinning a Michigan Wheel prop. I’m thinking cutlass bearing, but would appreciate any ideas. Many thanks, and Happy 4th to you all!

Possibly the bearing, or alignment issue (maybe strut got a bit bent in the impact and nobody notice?). Other possibilities -- stuffing box may be too tight or (took me a couple years to figure this one out!!!) packing nut may be cross-threaded. I had a squeal that only happened after shifting into neutral after idling ahead ... with the boat still moving ahead back pressure on the prop would still make it spin, combo of the shaft speed and nut being a bit skewed just kinda mapped to some harmonic frequency that only stopped if I put it back into gear (spinning faster) or the prop/shaft slowed down enough.

Thanks. All good advice. The squeal is only present in gear (forward) at >1300 RPM. Stuffing box might be the cause.

FWIW, I get this occasionally with my PYI dripless shaft seal

RWS