Helm vibration, Hunter 36e

[PNWE36]

Hello, I am new to this forum, I have read many of the posts and really appreciate the knowledge sharing.
My question is what is a normal amount of vibration at the helm on this Sailboat? I purchased a 2011 Hunter 36e last fall and have spent the winter fixing mostly minor deficiencies. The remaining deficiency was replacement of the cutless bearing. Vibration was noted during the sea trial and the survey noted the cause was the cutless bearing. Odd considering there is only 150 hours on the boat engine but there was no evidence to indicate a cause. The engine is a Yanmar 3YM30 coupled to a KMP2-1 transmission. The boat was taken out of the water early May. I had the local mechanic perform all the work.
There was nothing evident to cause the premature wear on the cutless bearing.
Shaft was straight, coupler looked good, no sign of damage to the strut.
Propeller had one blade that was out slightly. It was straightened and balanced.

New cutless bearing was installed, everything reassembled and at the same time the original shaft packing was replaced with a PSS seal.
The shaft did rest at the lower part of the shaft log so the mechanic moved it more to center when doing the alignment.

Once in the water the shaft could be heard bumping the shaft log on engine start. Also underway there was too much vibration above 2000 RPM at the helm and around the engine compartment. I went out under power for 4 hours.

After 3 weeks in the water the mechanic did the alignment again. It was out. He redid it. At the flange it was about .001" all around. He also used a dial indicator to check run out at the shaft and coulpler flange OD. All good. He did note the motor mounts were getting a little soft. He also noted that eliminating the shaft bumping on the shaft log on engine start is likely not possible without new engine mounts.
The vibration is now significantly reduced and hardly noticeable up to 2500 RPM. At 2900 RPM where I like to cruise vibration can be felt at the helm. Over 3000 RPM it gets worse. The vibration is really only noticeable on the wheel now, engine compartment area seems fine.
My previous boat was a 34 Beneteau 331 and it had no vibration to full throttle. It had 2000 hours on it with original mounts. It had a 3GM30F engine with the same transmission. The only time there was vibration at the helm was when the rudder bearing failed. The rudder on the Hunter is solid.
So as everything on the Hunter seems okay now, is it realistic to eliminate the helm vibration completely? It does bother me so if it can be eliminated without breaking the bank I will do it.
Thanks for reading this and looking forward to your comments.

 

[capta]

From your description, I'd lean towards your prop. Your mechanic has covered what I would have suggested.
Just because your prop (or any gear sent out for repair) was sent out for repair, that doesn't mean they did the job right. Sorry.

 

[Don S/V ILLusion]

the vibration is really only noticeable on the wheel now, engine compartment area seems fine.

vibration from anything within the drive train is “apparent in your feet”, not the wheel.

Hard to guess but I would focus more the cause being the rudder, post and bearings.

 

[Hayden Watson]

The only time I have had a helm vibrate was on my first boat which was a Clipper 26. With enough wind and the enough cojones to hang in there, the tiller would start to vibrate when she started to surf, and the speed log bumped over the 8-kt region, so I considered the vibration a good thing.
I had my brother who had a 3-point hydro drag boat always told me that he wasn't interested in sailing because it was too slow. One time when he came to visit me we went out on my boat for his first time on a sailboat. The wind was in the upper twenties, and we were sailing downwind with the big genoa. The first time we caught a wave and she took off on a sustained plane across the face of a wave on a deep broad reach, he was squealing and said "Wow, what that was fast, what was our speed" to which I responded, "just a bit over 10-knts." He got a rather surprised look on his face because on his boat, 120-knts was a normal run and it didn't get interesting until he was up in the range of +140.
He thought about it for a few minutes and said I guess that the ragged edge of anything operating at the maximum speed of its potential is fast, whether that is a kid's tricycle or an Indy race car. On that run, the rigging was signing, the hole boat was alive, and you could tell that any wrong move would not end well. It was fast in anyone's books.

 

[Ralph Johnstone]

My question is what is a normal amount of vibration at the helm on this Sailboat?

Shouldn't be anything worth noticing.

Are you able to do the work on your boat or are you at the mercy of the locals? A couple of things which have been done to date are open to question.

Vibration was noted during the sea trial and the survey noted the cause was the cutlass bearing. Odd, considering there is only 150 hours on the boat engine but there was no evidence to indicate a cause.

Highly unlikely at 150 hrs. Did you see the shaft move radially in the bearing or just took someone's word for it ? Also, I can't see only 150 hrs on a 12 YO engine. In the lower BC coast, over 50% of the time on the water is motoring due to the lack of wind.

After 3 weeks in the water the mechanic did the alignment again. It was out. He redid it. At the flange it was about .001" all around.

This has no meaning in the world of shaft alignment. Does this 0.001" refer to angular or radial misalignment or were you there for the re-alignment work ?

He did note the motor mounts were getting a little soft.

I understand the engine is only 12 YO and has 150 hrs. on it. The engine mounts are actually near new and did not need replacement. Did he demonstrate how he came to the conclusion the mounts needed replacement or were you there ?

Detecting the source of vibration on a drive train is a long drawn out process requiring many hours. Unless you have a good mechanic, things may not work out well and it becomes doubly difficult if you're not doing the work but relying on someone else to relay what they're doing.

A lot of work has been done on the drive and some of it does not seem right unless there were extenuating circumstances of which we are not aware.

Out of curiosity, you mention Thunderbird. Is that your marina ?

 

[PNWE36]

vibration from anything within the drive train is “apparent in your feet”, not the wheel.

Hard to guess but I would focus more the cause being the rudder, post and bearings.

 

[PNWE36]

From your description, I'd lean towards your prop. Your mechanic has covered what I would have suggested.
Just because your prop (or any gear sent out for repair) was sent out for repair, that doesn't mean they did the job right. Sorry.

Yes after exhausting the items that can be done in the water I might have to pull it out to have the prop rechecked. Thx.

 

[PNWE36]

The rudder was checked by the surveyor plus I checked it myself when we had it out of the water early May quite sure it is okay. The rudder bearing on our previous boat wore out. One of the signs was starting out while turned, the prop wash would cause the rudder to vibrate.

 

[PNWE36]

Shouldn't be anything worth noticing.

Are you able to do the work on your boat or are you at the mercy of the locals? A couple of things which have been done to date are open to question.



Highly unlikely at 150 hrs. Did you see the shaft move radially in the bearing or just took someone's word for it ? Also, I can't see only 150 hrs on a 12 YO engine. In the lower BC coast, over 50% of the time on the water is motoring due to the lack of wind.



This has no meaning in the world of shaft alignment. Does this 0.001" refer to angular or radial misalignment or were you there for the re-alignment work ?



I understand the engine is only 12 YO and has 150 hrs. on it. The engine mounts are actually near new and did not need replacement. Did he demonstrate how he came to the conclusion the mounts needed replacement or were you there ?

Detecting the source of vibration on a drive train is a long drawn out process requiring many hours. Unless you have a good mechanic, things may not work out well and it becomes doubly difficult if you're not doing the work but relying on someone else to relay what they're doing.

A lot of work has been done on the drive and some of it does not seem right unless there were extenuating circumstances of which we are not aware.

Out of curiosity, you mention Thunderbird. Is that your marina ?

I could do the work myself if I chose to. I do most work myself but on this job I already had a major hull prep for bottom paint job so I got the local mechanic to do it. I have interacted with him over the last 8 years buying parts from him to know I can trust him. I have not had a chance to talk with him after the last time he worked on it as I am travelling this week.
Yes 150 Hrs is very low, previous owner lived back east and used the boat more as a cottage when he came to Vancouver. Engine is like brand new. I did see the worn cutless myself. It looked like the rubber had broken down.

I was not there to watch the alignment and my comment about the .001" all around is abbreviated.

As far as the motor mounts are concerned I agree they should be fine. The mechanic mentioned they were a little soft as information and wasn't suggesting they needed to be changed. Before changing them I will find out if there is a specification on allowable movement and verify they are out of spec.

As you mentioned getting the last bit of vibration out may be a long drawn out process and I may have to do that myself through a little trial and error.
Yes the boat is kept at Thunderbird Marina.

 

[PNWE36]

Thanks to everyone for your replies. I have concluded from this I shouldn't feel any noticeable vibration at the helm and appreciate your input to help diagnose the problem.