Video Link - Still Trying to Diagnose Squeal in Forward

[Therapy]

Good to hear you found it.

Best of luck.

[Chief Engineer]

I followed this...glad you found the problem

[Northeaster]

Update - I am not a happy camper!

After taking the prop shaft out in the fall / winter, and finding scoring marks where misalignment had caused the shaft to rub against the side of the stern tube and the edge / side of the bronze suffing box, I figured I had found the trouble. I centered the shaft near the center of the stern tube (What do I mean "near" the center? Well, the stern tube is not perfectly aligned with the propeller shaft and strut, so I did my best to center the shaft, so it would not rub again.)
Then, I moved and adjusted my engine mounts so the engine was aligned with the prop shaft.

The boat just went in the water, and I ran the engine for a while today, tied to the dock. Same as last year - Squeals in forward and not in reverse.
I am back to thinking that it must be a bearing or something in the transmission. Other than the squealing noise, it runs fine, and we put up with the noise for the last 2 years. Looks like I will put up with it again this year, and likely pull the trannie next year. Had it apart a couple of years ago, to lap the drive cones, as it had not been going into gear well. Works A1 now, other than the squealing noise.

We only motor for 5-10 minutes in and out of the marina, and on the occasional, infrequent low wind days, so I am not going to pull the transmission now that we are getting into prime sailing season!.

[Northeaster]

Hi Folks,
Decided to continue this thread, as.... well.. the saga continues.

Enjoyed great summer - lots of sailing, and some motoring, still putting up with the squeal sound in fwd (video link of noise on page 1)

Now that boat is stored indoors again for the winter, I have just removed the transmission and had a quick look.
- The damper plate looks quite uneven / warped a bit, and a couple of the springs have some flat spots on the sides of them (as if they have been rubbing on something (likely flywheel I guess). Will price a new damper disk, complete with springs.
- The propeller shaft turned easily, while gearbox was still attached (in neutral) and I don't think it is rubbing on the stern tube or stuffing box.
- There seems to be quite a bit of play / clearance in the input shaft, as I am able to pull / push it in and out. there is also some side to side play.
- there is a very slight amount of play in the output shaft. (in and out)

When I removed the bell housing / mounting flange, I did not see any shims behind the bearing races on the output shaft, and on the input shaft there is what looks like a washer with a slot in it - Are shims a full circle, or do they have slots in them, like 1/4 - 3/8" wide??

I have the manual, but I am unclear as to how I am supposed to measure the clearances. It shows what the clearances should be, but how do you go about measuring the distance between the races, when one race is in the end of the gearcase, and the other is in the |(removed) mounting flange?? Do I need to put the mounting flange back on 1st?
If someone could explain how measure, in simple laymans terms, I would really appreciate it.

[Northeaster]

Posting a couple of pics of the old damper plate / disk. If you look closely, you can see some wear marks on a couple of the springs, where they were obviously rubbing on something. I think that "something" would be the flywheel. Not sure if this is the noise culprit, but I think that the weakened springs (25 years old) may have caused more play between the inner and outer damper plate parts, and this may have caused some rubbing against the flywheel, as it turned. At 1500 - 3000 rpms, I am thinking that could have caused some noise.

Priced the damper plate at local Yanmar dealer (Halifax, Nova Scotia). Was ready for a hefty price, as I saw list prices of about $283 on -line at Torreson's, etc. But, was not prepared for the $580 local (robbery) quote. Luckily, found a new one on Ebay for $149, and $10 shipping.
May have to ship / pick it up in Maine, but am over that way every few months anyway.

[paal]

Hi, thanks for a very informative thread. In our sailboat, a Comfort 30 with a Yanmar 2GM and Kanzaki 4something tranny we hade the e-x-a-c-t same sound and cannot seem to narrow it down. The tranny was rebuilt at great expense which did not remove the sound sadly.

Did you have any success in removing the sound after overhauling the damper plate?

[Northeaster]

Hi - unfortunately - no, it did not fix the problem. At this point I have learned to live with it, but would love to know what it is. Someone had mentioned the possibility of improper shims in the trannie, but we put all of the original shims back in, so I am not sure.

The engine and trannie work well otherwise, but as they are 1982, and the engine is raw water cooled, I am not putting anymore effort / money into checking. Hopefully it works for 10 more years, but I will save a bit of cash for a repower if necessary someday, or kee pan eye out for a used replacement, something with 5 - 10 year on it, for a good deal.

Let us know if you find what is causing your issue!

[paal]

>improper shims in the trannie

Hm. The trannie was overhauled at a renowned Yanmar mechanic so I doubt they would let than one go. The damper plate is rather expenice (288 USD, yikes!) so if we can skip that we'd appreciate it. Maybe just change out the Cutlass bearing instead first, then maybe the pack box to narrow things down from cheaper to more expensive.

[NCboatrx]

I have just watched and listened to your short video. I suspect that you have a singing propeller. Any prop shop can put an anti-squeal edge on it for you.

[Northeaster]

NCboat - Thanks for the input!!! That was one thing I had meant to do this year, while out of the water - take it t oa shop and have them file the edge to see if this made a difference.

Paal - has your's always done this, or when did it start?
Did you change props or have any work done to it?

[paal]

We took possession of the boat last year in July. When we had the test ride before signing the contract, the noise was not there or we didn't notice it. It happens on all RPMs in forward gear only. All bearings and more in the tranny has been changed out lately... What kind of tranny did you have? Ours os a Yanmar / Kanzaki KM2A

[Northeaster]

95% sure mine is a KM2A as well, or possibly a KM2P.

If it was your prop singing, was it perhaps a bit dirty during the test drive - did you happen to clean it, and perhaps that would expose the sharper edge and great the noise?

I was going to have my prop filed a bit duller on the edge, or do it myself- there are good articles on the net about singing props and how to file to solve it.
But, my prop was repitched and cut smaller diameter by a very experienced prop guy, so I am not sure if that's the cause.
I am like you, I don't know if mine did it before the repitching or not, as it was a few years ago, and I had the whole thing out, and realinned it, so the noise could still the rubbing on the stuffing box or something else.

[paal]

So, after roughly a year, there is little positive development in the whiny gearbox / propeller / whatever process. This year we have:

* Changed the cutless bearing, which did actually could stand to be changed. The play in the space of the axel and cutless bearing wasn't awful, but it was completely, chock full of grease from the grease stuffing box. When we got the boat, the previous owner (and, as we know, the previous owner is always an idiot) told us to "tighten the grease cup 1/2 turn for every 30 minutes the engine has been running. That's what he's been doing for years, and it completely filled the whole stern tube with grease, effectively hindering all water cooling of the axel and cutless. What. A. Tool.

* Changed the stuffing box. Since the old stuffing box was some 30 years old, and completely ruined by the overuse of grease from the Previous Owner, we changed it out with a new, oil lubed one. It was the only one that would fit, but it is also more convenient as we don't have to think about the grease at all.

Did the sound disappear? No. Actually, we now have another problem to follow up on the previous one. The gear has started to slip a bit going in forward gear, the slipping can be mediated by changing the RPMs a bit, and happens at several different RPMs.

So, I took the question to an internet expert, who offered another answer. It might be the gears themselves are worn. You can read the conversation here:
http://www.justanswer.com/boat/8icgl...-problems.html

The short answer is: "The transmission needs to be rebuilt. The slipping is the cone clutch slipping do to wear. The whine is the gears so basically the transmission is worn badly and should be repaired. You should be able to get the repair done for around $500-750. The gears and cone run $240.31. Then whatever else that needs to be replaced depending on how they look."

Since the sound is in forward gear, and only in forward gear, I do not suspect the damper plate to be the culprit. The damper plate does the exact same movement in forward gear as it does in reverse after all.

If you have anymore updates, Northeaster, I'd really appreciate to hear about them. Good luck going forward.