Dripless Shaft Seal Noise

[salemsailor]

I had a drip-less prop shaft seal installed this year (PSS?). At certain RPMs I get a 'clack-clack-clacking' noise. If I speed up or slow down it will go away. Seems to occur about 1/8 full throttle and again a little less than 3/4 throttle.

Is this normal or something to worry about?

The clacking doesn't seem to be from the engine as it only happens when in gear and the shaft turns freely when in neutral. Never had this noise before the seal was installed.

Otherwise it works great with no problems.

Boat is a 32' Hunter 1987 with a 2GM Yanmar.

Any insight appreciated!

 

[Rick D]

Shaft Centered In Log?

If the shaft isn't centered in the log, you can sometimes get some clatter from the shaft hitting the log. Likewise if the engine mounts are weak or broken. If it's minor, wait until haul out to check.

 

[Witzend]

Well, generally the noise is not caused from the shaft hitting the log, but from the shaft contacting the fiberglass the surrounds the exit hole. Chances are it's hitting the bottom of this exit hole due to the engine mounts settling over time. Check your engine alignment, and when on the hard next, examine the gap around the shaft and exit hole for centering. Also, check for cutlass bearing for wear because of the mis-alignment.

 

[walmsleyc]

The log is usually the metal fitting that lines the fiberglass surrounding the exit hole. So I think we are all talking about the same thing.

I have both recently install the PPS shaft seal and had problem with the shaft hitting the log due to sagging/soft engine mounts. I was able to shim and adjust my mounts to recenter the shaft in the log. Hopefully I'll get another year or so out of my old mounts. I will still get a knocking on occasion when taking a corner fairly hard. The engine will lean over a little more on it's mounts, and allow the shaft to get too close to the log, but this is only for very short period while taking a hard turn under medium to full power.

Adding a PSS shaft seal has been rumored to make this knocking more likely because a traditional shaft packing provides somewhat more support for this part of the shaft than does a PSS shaft seal, and thus a PSS seal allows it to more easily touch the log.

Chris

 

[seadaddler]

No clacking

I had my 2007 H-36 when brand new installed PSS and have never had any
noise at all,I do get water out of the air vent hose when using reverse at times.
Sounds like you need to check your motor mounts and alignment.
Nick