My 2006 NT32 has a new engine vibration.  I just had the shaft pulled, prop balanced, and replaced both cutlets bearings and the pss.  Now I notice a vibration where there was none before.  It is right at 1000 rpm.  The yard did a sea trial with me and they are now going to check the alignment to be sure it’s ok.  They don’t think it’s out of spec and acknowledge that I know my boat best, but they don’t feel anything that seems like it’s out of balance.

The vibration tunes out as you raise rpm.  Motor mounts?  Coincidence.

Ned advice.

David

WILSON NT32 260
Santa Barbara

Sent from my iPad

About 4 months ago we had the PSS dripless shaft seal replaced on our 2008 NT 32.  When we took her out, we noticed vibration at 1850 rpm (+/- 50). Ran with it for a couple of weeks to confirm.  The mechanics detached the shaft from the transmission coupling and spent time getting the tolerances back in shape.  This was done by adjusting both the shaft and the engine mounts.  About 3-4 hours of work.  Runs fine now.

For what it is worth. Ours might be a totally different issue.

Cheers,

Angelo
Salish Star
NT32-300

-----Original Message-----
From: David Wilkie Owen via Sentoa sentoa@lists.sentoa.org
Sent: Tuesday, August 17, 2021 12:56 PM
To: sentoa@lists.sentoa.org
Cc: David Wilkie Owen dwowen@cox.net
Subject: [Sentoa] Engine vibration

My 2006 NT32 has a new engine vibration.  I just had the shaft pulled, prop balanced, and replaced both cutlets bearings and the pss.  Now I notice a vibration where there was none before.  It is right at 1000 rpm.  The yard did a sea trial with me and they are now going to check the alignment to be sure it’s ok.  They don’t think it’s out of spec and acknowledge that I know my boat best, but they don’t feel anything that seems like it’s out of balance.

The vibration tunes out as you raise rpm.  Motor mounts?  Coincidence.

Ned advice.

David

WILSON NT32 260
Santa Barbara

Sent from my iPad

Sentoa mailing list -- sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.org

My thoughts on this (for what that is worth 🙂) are that anytime you remove the shaft from the transmission and take the coupler off the shaft, it really should be "refitted" and the alignment checked. You are talking about thousands of an inch and some experts recommend sending the shaft and coupler to a machine shop for the refitting. I never went that far, but we did require an alignment after doing the work you describe.
I think Angelo has it right.
Good luck,
Tom Easterbrook
formerly Pilitak NT 37-068
Nanaimo, BC

From: angelo amuzzin.com via Sentoa sentoa@lists.sentoa.org
Sent: August 17, 2021 8:47 PM
To: South East Nordic Tugs Owners' Association (SENTOA) sentoa@lists.sentoa.org
Cc: angelo amuzzin.com angelo@amuzzin.com
Subject: [Sentoa] Re: Engine vibration

About 4 months ago we had the PSS dripless shaft seal replaced on our 2008 NT 32.  When we took her out, we noticed vibration at 1850 rpm (+/- 50). Ran with it for a couple of weeks to confirm.  The mechanics detached the shaft from the transmission coupling and spent time getting the tolerances back in shape.  This was done by adjusting both the shaft and the engine mounts.  About 3-4 hours of work.  Runs fine now.

For what it is worth. Ours might be a totally different issue.

Cheers,

Angelo
Salish Star
NT32-300

-----Original Message-----
From: David Wilkie Owen via Sentoa sentoa@lists.sentoa.org
Sent: Tuesday, August 17, 2021 12:56 PM
To: sentoa@lists.sentoa.org
Cc: David Wilkie Owen dwowen@cox.net
Subject: [Sentoa] Engine vibration

My 2006 NT32 has a new engine vibration.  I just had the shaft pulled, prop balanced, and replaced both cutlets bearings and the pss.  Now I notice a vibration where there was none before.  It is right at 1000 rpm.  The yard did a sea trial with me and they are now going to check the alignment to be sure it’s ok.  They don’t think it’s out of spec and acknowledge that I know my boat best, but they don’t feel anything that seems like it’s out of balance.

The vibration tunes out as you raise rpm.  Motor mounts?  Coincidence.

Ned advice.

David

WILSON NT32 260
Santa Barbara

Sent from my iPad

Sentoa mailing list -- sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Sentoa mailing list -- sentoa@lists.sentoa.org
To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Aye, there’s the rub…..

The taper was faced.  The prop was balanced, adjusted, checked and polished by a top notch shop.  Both Cutless bearings were replaced.  The shaft was faced to the coupler.  The shaft was checked for runout in a lathe by a top notch yard that services commercial boats of all sizes.  These guys work on massive fishing boats and coast guard boats and the like.

It's weird.  My diver checked the prop today.  He said it was tight, there was no play and didn’t show any signs of a strike.  Not surprising, because I would have known if it hit something hard enough to cause damage.

He said when he turned the prop by hand, that it had a “singing” or “humming” sort of feeling when turned in forward, but not in reverse.  He didn’t think it was pronounced or unusual enough to cause a vibration.

David

David Wilkie Owen

mailto:dwowen@cox.net dwowen@cox.net

“WILSON”  Nordic Tug 32-260

Santa Barbara, CA

From: Fire Fighter via Sentoa sentoa@lists.sentoa.org
Sent: Thursday, August 19, 2021 3:41 PM
To: South East Nordic Tugs Owners' Association (SENTOA) sentoa@lists.sentoa.org
Cc: Fire Fighter firehoser75@hotmail.com
Subject: [Sentoa] Re: Engine vibration

My thoughts on this (for what that is worth 🙂) are that anytime you remove the shaft from the transmission and take the coupler off the shaft, it really should be "refitted" and the alignment checked. You are talking about thousands of an inch and some experts recommend sending the shaft and coupler to a machine shop for the refitting. I never went that far, but we did require an alignment after doing the work you describe.

I think Angelo has it right.

Good luck,

Tom Easterbrook

formerly Pilitak NT 37-068

Nanaimo, BC

From: angelo amuzzin.com via Sentoa <sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org >
Sent: August 17, 2021 8:47 PM
To: South East Nordic Tugs Owners' Association (SENTOA) <sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org >
Cc: angelo amuzzin.com <angelo@amuzzin.com mailto:angelo@amuzzin.com >
Subject: [Sentoa] Re: Engine vibration

About 4 months ago we had the PSS dripless shaft seal replaced on our 2008 NT 32.  When we took her out, we noticed vibration at 1850 rpm (+/- 50). Ran with it for a couple of weeks to confirm.  The mechanics detached the shaft from the transmission coupling and spent time getting the tolerances back in shape.  This was done by adjusting both the shaft and the engine mounts.  About 3-4 hours of work.  Runs fine now.

For what it is worth. Ours might be a totally different issue.

Cheers,

Angelo
Salish Star
NT32-300

-----Original Message-----
From: David Wilkie Owen via Sentoa <sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org >
Sent: Tuesday, August 17, 2021 12:56 PM
To: sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org
Cc: David Wilkie Owen <dwowen@cox.net mailto:dwowen@cox.net >
Subject: [Sentoa] Engine vibration

My 2006 NT32 has a new engine vibration.  I just had the shaft pulled, prop balanced, and replaced both cutlets bearings and the pss.  Now I notice a vibration where there was none before.  It is right at 1000 rpm.  The yard did a sea trial with me and they are now going to check the alignment to be sure it’s ok.  They don’t think it’s out of spec and acknowledge that I know my boat best, but they don’t feel anything that seems like it’s out of balance.

The vibration tunes out as you raise rpm.  Motor mounts?  Coincidence.

Ned advice.

David

WILSON NT32 260
Santa Barbara

Sent from my iPad

Sentoa mailing list -- sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org  To unsubscribe send an email to sentoa-leave@lists.sentoa.org mailto:sentoa-leave@lists.sentoa.org

Sentoa mailing list -- sentoa@lists.sentoa.org mailto:sentoa@lists.sentoa.org
To unsubscribe send an email to sentoa-leave@lists.sentoa.org mailto:sentoa-leave@lists.sentoa.org

It sounds like one of the Cutless bearings might be slightly tight or slightly misaligned. Every engine/drive train has resonant frequencies. If the “singing” or “humming” happens to match one of the resonant frequencies there could be an overall vibration.

Probably nothing to worry about if you have already done a thorough job as stated. It is likely to go away with time.

Gene Fuller

Yorkshire Rose

NT 37-136

David, Sounds like you did everything right. My guess is that your alignment (adjusted with the mounts) is most likely the cause of your vibration. It is possible that the mounts have (over time) gone bad and by luck just showing up now, but most likely only an adjustment is needed. Your "experts" should be able to figure this out and eliminate the vibration. In my case, an alignment adjustment did the trick.
Tom

From: David Wilkie Owen via Sentoa sentoa@lists.sentoa.org
Sent: August 19, 2021 11:08 PM
To: 'South East Nordic Tugs Owners' Association (SENTOA)' sentoa@lists.sentoa.org
Cc: David Wilkie Owen dwowen@cox.net
Subject: [Sentoa] Re: Engine vibration

Aye, there’s the rub…..

The taper was faced.  The prop was balanced, adjusted, checked and polished by a top notch shop.  Both Cutless bearings were replaced.  The shaft was faced to the coupler.  The shaft was checked for runout in a lathe by a top notch yard that services commercial boats of all sizes.  These guys work on massive fishing boats and coast guard boats and the like.

It's weird.  My diver checked the prop today.  He said it was tight, there was no play and didn’t show any signs of a strike.  Not surprising, because I would have known if it hit something hard enough to cause damage.

He said when he turned the prop by hand, that it had a “singing” or “humming” sort of feeling when turned in forward, but not in reverse.  He didn’t think it was pronounced or unusual enough to cause a vibration.

David

David Wilkie Owen

dwowen@cox.netmailto:dwowen@cox.net

“WILSON”  Nordic Tug 32-260

Santa Barbara, CA

From: Fire Fighter via Sentoa sentoa@lists.sentoa.org
Sent: Thursday, August 19, 2021 3:41 PM
To: South East Nordic Tugs Owners' Association (SENTOA) sentoa@lists.sentoa.org
Cc: Fire Fighter firehoser75@hotmail.com
Subject: [Sentoa] Re: Engine vibration

My thoughts on this (for what that is worth 🙂) are that anytime you remove the shaft from the transmission and take the coupler off the shaft, it really should be "refitted" and the alignment checked. You are talking about thousands of an inch and some experts recommend sending the shaft and coupler to a machine shop for the refitting. I never went that far, but we did require an alignment after doing the work you describe.

I think Angelo has it right.

Good luck,

Tom Easterbrook

formerly Pilitak NT 37-068

Nanaimo, BC

From: angelo amuzzin.com via Sentoa <sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org>
Sent: August 17, 2021 8:47 PM
To: South East Nordic Tugs Owners' Association (SENTOA) <sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org>
Cc: angelo amuzzin.com <angelo@amuzzin.commailto:angelo@amuzzin.com>
Subject: [Sentoa] Re: Engine vibration

About 4 months ago we had the PSS dripless shaft seal replaced on our 2008 NT 32.  When we took her out, we noticed vibration at 1850 rpm (+/- 50). Ran with it for a couple of weeks to confirm.  The mechanics detached the shaft from the transmission coupling and spent time getting the tolerances back in shape.  This was done by adjusting both the shaft and the engine mounts.  About 3-4 hours of work.  Runs fine now.

For what it is worth. Ours might be a totally different issue.

Cheers,

Angelo
Salish Star
NT32-300

-----Original Message-----
From: David Wilkie Owen via Sentoa <sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org>
Sent: Tuesday, August 17, 2021 12:56 PM
To: sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org
Cc: David Wilkie Owen <dwowen@cox.netmailto:dwowen@cox.net>
Subject: [Sentoa] Engine vibration

My 2006 NT32 has a new engine vibration.  I just had the shaft pulled, prop balanced, and replaced both cutlets bearings and the pss.  Now I notice a vibration where there was none before.  It is right at 1000 rpm.  The yard did a sea trial with me and they are now going to check the alignment to be sure it’s ok.  They don’t think it’s out of spec and acknowledge that I know my boat best, but they don’t feel anything that seems like it’s out of balance.

The vibration tunes out as you raise rpm.  Motor mounts?  Coincidence.

Ned advice.

David

WILSON NT32 260
Santa Barbara

Sent from my iPad

Sentoa mailing list -- sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.orgmailto:sentoa-leave@lists.sentoa.org

Sentoa mailing list -- sentoa@lists.sentoa.orgmailto:sentoa@lists.sentoa.org
To unsubscribe send an email to sentoa-leave@lists.sentoa.orgmailto:sentoa-leave@lists.sentoa.org