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Shaft Alignment

Posted: September 27th, 2023, 6:56 pm
by Tireless
I had a survey done buy a reputable surveyor in our area for insurance. He advised that I should have a shaft alignment done. He advised that he saw an irregularity in the gaping around the cutlass bearing. To the best of my knowledge, it has been a while since one had been done. I spoke to the mechanic at our marina and he advised that he agreed with the surveyor.

The mechanic went onto my boat yesterday and commenced the shaft alignment process. When he removed the bolts from the couplings between the shaft and the transmission, the shaft coupling moved over which indicated a significant misalignment on both engines. It was about 3/4 “ on the Port side and less on the Starboard engine.

The bolts on the mounts on the Starboard engine were loose and could be turned by hand. There was no issue for him to raise and lower the motor on the mounts in an attempt to line up the couplings, however, he was not able to move the motor on the mounts from right to left to line things up, which was required.

He advised me that the bolts on the motor mounts pass through a round hole and not a slot that would allow for a right to left adjustment. He advised that a remedy would be to drill out the mounts to turn the round hole into a slot to allow for an adjustment.

I don’t know the answer. It seems that there has to be a better way to move the motor from right to left without removing and drilling out the mounts.

He was able to reattach the transmission and shaft couplings, however it would still not be aligned within the acceptable tolerance. I was advised that it was better than before, but requires more adjustment.

Has anyone had this experience or has advice on how alignment can be achieved. Should the holes in the mounts be slots instead of holes, if so, not sure why Carver would do this. I have not examined the mounts in the boat, but I will this weekend.

There has to be a better way.

Thank you in advance

Greg

Re: Shaft Alignment

Posted: September 27th, 2023, 7:09 pm
by bud37
Greg....viper will know one heck of a lot more about this than I do that is for sure. I have a question though.....did the surveyor happen to mention if he thought the misalignment was strictly due to the engine mountings or could it be a combination of a few things considering it is both sides roughly the same.

Might be something to look at in depth when the boat comes out......struts etc.....should be soon Port Severn.

Edit ...is the boat out now ?....if so, see the clearance where the shafts go thru the stern tube, he did say there was wear on the bearings.

Re: Shaft Alignment

Posted: September 27th, 2023, 7:24 pm
by Tireless
I spoke to Barry about the struts and he advised that he did not think the struts were the problem. It would take a hell of an impact to push them out of line. I spoke to the original owner who advised there was never any strut work done on the boat. So I cant be sure, but I think they should be good.

I will have the struts looked at when the boat is out next Monday. Already spoke with the mechanic about that.

Thanks for you input.

Greg

Re: Shaft Alignment

Posted: September 27th, 2023, 7:42 pm
by km1125
Do your mounts go directly into the stringers, or to a bracket bolted to the stringers? If you post a couple pics of the engine mounts you have, it would be easier to see what would have to be done.

Below is one pic I found for a D6 mount. Not sure if this is the same as yours. Looks like there are slots in the mount that should allow some horizontal movement, but maybe not enough in your case. Seems like you could enlarge those slots a little without big issues but still wonder if it would be enough.

I also wonder where the shafts are ending up relative to the stuffing boxes. Are they now centered or would they still be offset to one side?

volvo_d6_mount.jpg

Re: Shaft Alignment

Posted: September 27th, 2023, 8:06 pm
by Viper
Greg, post an engine serial number.

Re: Shaft Alignment

Posted: September 27th, 2023, 8:29 pm
by Tireless
Km1125, I am heading up to the boat tomorrow to have a closer look at the mounts. I am not sure what you mean by the term “stuffing boxes”.

Engine serial numbers are Port “2006004428 and Starboard “2006004351.

Thanks for you assistance.

Greg

Re: Shaft Alignment

Posted: September 27th, 2023, 8:32 pm
by bud37
You said Barry...are we talking RaKon...? No particular reason, just curious.

Re: Shaft Alignment

Posted: September 27th, 2023, 8:43 pm
by Tireless
Bud37, Yes. No mention of wear on the bearings, in fact he said cutlass bearings are fine.

Greg

Re: Shaft Alignment

Posted: September 28th, 2023, 8:26 am
by km1125
Tireless wrote:Source of the post Km1125, .... I am not sure what you mean by the term “stuffing boxes”. ....

Where the shafts go through the hull.

I guess since a lot of folks have dripless seals these days the "stuffing" part could be misleading and I probably should have said "stern tube" or "shaft log". There should be very little clearance between that tube and the actual shaft, so moving the engine left or right (or even up and down) too much could result in contact.

Re: Shaft Alignment

Posted: September 28th, 2023, 9:53 am
by Tireless
Km1125, hopefully the mechanic will ensure that. I will look for sure. Your information on the D6 engine mounts was very helpful. I will look at that today when I go up to the boat and have a conversation with the mechanic.

Have to prep the boat for haul out on Monday, season blew past.

There appears to be room for a horizontal adjustment at the base of the mounts at the stringer.

Thank you

Greg