Shaft / Prop / Bearing High Pitch Squeak

[TommyB]

Morning,
After basically having the entire running gear redone replaced, still have the high pitch loud squeak.
Shafts trued / unbent, props balanced , new cutlass bearings, shaft logs etc etc.
Only thing not replaced were the struts.

So we splashed yesterday and I'll be danged.. Starboard shaft is still making the noise, but not only that the port side has started that high pitch noise. Almost as if they are hitting a low spot or something. The faster the props turn the more longer and continuous this squalling noise is until it is one long squall

The only thing left is engine alignment which is next Saturday.
Do props make some harmonic singing noise when spinning? And why would the port side start making this noise after being balanced and trued?

Oh well, will keep you updated and let's hope the engine alignment fixes this, as I don't want to replace bearings again in 600 miles

 

[rsmith]

I had a friend with a 46c that sharpened his wheels to a knife edge. It gave them a god awfull wissle

 

[Tinman]

Have been told flat edges on blades can make a prop whine and smoothing any sharp edges with a file should eliminate the sound. Can you tell if the sound is coming from the prop area or farther forward?

 

[saltshaker]

I had a friend with a 46c that sharpened his wheels to a knife edge. It gave them a god awfull wissle

X2. I had the same thing happen to me after sending a set of wheels out to be tuned. Props looked great and had a nice sharp edge. They would sing like mad. As for engine alignment, that should have been checked/adjusted when all the other work was done. Are the shafts centered in the struts? How much did you run the boat? I had a slight noise after rep,lacing all 4 cutlass bearings but it went away within the first hour of operation.

 

[TommyB]

X2. I had the same thing happen to me after sending a set of wheels out to be tuned. Props looked great and had a nice sharp edge. They would sing like mad. As for engine alignment, that should have been checked/adjusted when all the other work was done. Are the shafts centered in the struts? How much did you run the boat? I had a slight noise after rep,lacing all 4 cutlass bearings but it went away within the first hour of operation.

Only ran the boat for about 15 mins.
They did not want to align the engine on the hard, so will do that this coming Saturday.

Other work was being done also, ie New 3000w inverter, new wiring, etc etc etc..was the reason could only motor around for 10 mins or so.

I know I'll need about 600lbs of lead now to counter-balance the 5 new AGM's sitting on the port side. Was no room to put any on the starboard side due to hot water heater. Got about a 5" list to port now.

 

[SKYCHENEY]

I had singing of a prop once after having them tuned, but it was only at certain RPM, like 700-1100. After that, it went away.

I fixed the problem by changing props. The "singers" are now my spares.

 

[TommyB]

Just finished a 600 mile trip over 14 days. Abacos Islands and Back.
As mentioned above, props, shafts, and coupling were sent out and worked on.
New Cutlass bearing etc. Engine aligned to 3 thousandths.
New shaft log rubber thing also

Still having issues. Starboard side still make a god awefull squeaking sound
and the port side shaft is now moving up and down at the shaft log.

I can turn the shafts by hand when I dove them the other day, so they are not in a tight bind.
not sure where to go next?
any ideas other then buy a new boat

 

[saltshaker]

Man you can't catch a break with this boat! Don't get too discouraged it'll come together at some point. I'm really surprised you're having all these issues as that boat appeared to be well maintained. You need to figure out what's going on fast. Something is seriously wrong if the shaft is moving up and down. When everything was out, did they pull any of the struts? Make sure nothing is loose. Did they check the transmissions when the shafts were out? If the running gear is true and the alignment is on, then you have an issue with the gears, engines or mounts. Look at the mounts and see if they look like they are twisted, collapsing or distorted in anyway. Check to see that there isn't any damage to the stringers or engine beds. Go for a ride and have a mechanic see what's going on at different speeds.

 

[Tinman]

Ditto to saltshaker.

 

[TommyB]

Man you can't catch a break with this boat! Don't get too discouraged it'll come together at some point. I'm really surprised you're having all these issues as that boat appeared to be well maintained. You need to figure out what's going on fast. Something is seriously wrong if the shaft is moving up and down. When everything was out, did they pull any of the struts? Make sure nothing is loose. Did they check the transmissions when the shafts were out? If the running gear is true and the alignment is on, then you have an issue with the gears, engines or mounts. Look at the mounts and see if they look like they are twisted, collapsing or distorted in anyway. Check to see that there isn't any damage to the stringers or engine beds. Go for a ride and have a mechanic see what's going on at different speeds.

Don't think they checked the struts at all.
Slapped some go-jo on them, and shafts slid right in.
No on Transmission check.
I guess engine check amounted to, feeler gauge and lower the fronts of the starboard and port engines.
Will find out more this week on what they plan on doing to fix this.

 

[saltshaker]

I would not run the boat until you straighten this out. Unless you've hit something the shafts and props should be true. The fact that the shaft is visibly moving is an indication of something that is loose or has too much play. A shaft wobble can quickly take out your cutlass bearings and transmission, particularly the output shaft bearings.

 

[rsmith]

Just finished a 600 mile trip over 14 days. Abacos Islands and Back.
As mentioned above, props, shafts, and coupling were sent out and worked on.
New Cutlass bearing etc. Engine aligned to 3 thousandths.
New shaft log rubber thing also

Still having issues. Starboard side still make a god awefull squeaking sound
and the port side shaft is now moving up and down at the shaft log.

I can turn the shafts by hand when I dove them the other day, so they are not in a tight bind.
not sure where to go next?
any ideas other then buy a new boat

If you can move the coupling up and down with noticeable movement while still bolted to the trans the thrust bearing that the trans output shaft runs in is shot.

 

[saltshaker]

If you can move the coupling up and down with noticeable movement while still bolted to the trans the thrust bearing that the trans output shaft runs in is shot.

That's what happened with my M20 gears on my 46C. Mine was tight until I split the coupling, then the play at the output flange was very obvious.

 

[mike]

Don't think they checked the struts at all.
Slapped some go-jo on them, and shafts slid right in.
No on Transmission check.
I guess engine check amounted to, feeler gauge and lower the fronts of the starboard and port engines.
Will find out more this week on what they plan on doing to fix this.

If you had to lower the fronts on both engines, I would check the rear mounts to make sure they are not sagging esp. if you have the old style orig DD mounts. It is easy to misalign the shafts because of the natural sag caused by the unsupported distance of aprox 40+ inches between the coupling and the cutless bearing, esp. if you also have the large and heavy shaft coupling. The net effect of the sag is it appears to look as though the shaft angle is shallower than before. If this is the case, over time left unrepaired it will destroy the rear bearing on the M20´s. Learned this the hard way. Good luck.

 

[34Hatt]

If you had to lower the fronts on both engines, I would check the rear mounts to make sure they are not sagging esp. if you have the old style orig DD mounts. It is easy to misalign the shafts because of the natural sag caused by the unsupported distance of aprox 40+ inches between the coupling and the cutless bearing, esp. if you also have the large and heavy shaft coupling. The net effect of the sag is it appears to look as though the shaft angle is shallower than before. If this is the case, over time left unrepaired it will destroy the rear bearing on the M20´s. Learned this the hard way. Good luck.

This made me remember something I found with sag and mounts that were to low.
When I bought mine it was all F-ed up and the shaft was rubbing inside the shaft tube near the neck could only see it after taking the packing gland off. I aligned it then on the hard with shaft centered then checked it in the water which it never changes from hard to water

 

[Boatnut]

I always wonder why some yards will replace cutlass bearings, and recondition the props, yet they never check strut alignment or check the shafts for bends or twists. So many time we hear of these issues after this work is done. It doesn't take much misalignment to cause a problem.

 

[TommyB]

I always wonder why some yards will replace cutlass bearings, and recondition the props, yet they never check strut alignment or check the shafts for bends or twists. So many time we hear of these issues after this work is done. It doesn't take much misalignment to cause a problem.

Shafts and props were both done at General Prop out of Tampa
But, the struts were no done. No idea why. I wanted it fixed right, and still have issues.