ENGINE NOISE-DAMPER REPLACEMENT?

[KevinMc]

Leigh, what was the part number for PYI for the high deflection damper plate you ordered? Thanks!

[wolfe10]

PYI high deflection dampener plate, RD-22AM-4, $232 verified correct 12/5/16 by Kenneth Planck with PYI.

[Dutch]

To compliment other posts about the M35B damper plate, here is my experience. At slightly over 700 engine hours, I discovered black/grey power in the starboard rear area of my engine compartment. I first though it was from the alternator belt but not so. Shortly later I noticed a chattering sound in idle that would decrease when engine rpm increased. I think the clattering had been there for some time but I just did not pay attention to it. Based on other posts, I decided the problem was likely the damper plate. I disconnected the transmission output shaft from the prop shaft, raised the engine rear, removed the transmission, and removed and replaced the damper plate. The damper plate has a non-metallic center which was coming apart with chunks in the bell housing bottom. These chunks were being ground into fine power that was blowing out the timing mark viewing hole in the starboard side of the bell housing. I replaced the damper plate and problem solved. Upon request, I will email a fairly detailed summary with pictures of how I raised the engine rear and removed and replaced the damper plate. I did all the work and the damper plate cost $404.32 at R. B. Grove, Inc. in Pensacola. Below is a description of the pictures.

Picture Comments:
DP01.jpg: New damper plate on left and old on right.
DP02.jpg: New damper plate.
DP03.jpg: Old damper plate.
DP04.jpg: Old damper plate showing chunks removed from bell housing.
DP05.jpg: Part number tag for new damper plate.
DP06.jpg: Port rear engine mount area showing bolt used to raise engine rear.
DP07.jpg: Wood piece used to keep pressure on dripless seal.
DP08.jpg: New damper plate installed in bell housing.
DP09.jpg: Another shot of new damper plate in bell housing.
DP10.jpg: Transmission reinstalled and engine rear still raised.
DP11.jpg: Another shot of transmission output shaft and prop shaft flanges disconnected.

[kimmiya]

Sorry, original post below had wrong High Deflection damper plate model. It should have been PYI R&D Marine 22AM4. Corrected below.

I have a 2004 Catalina 350 (Hull #221) with the Universal/Westerbeke M35B and a Hurth ZF 15 MA (HBW 150A) transmission. The damper plate that was in the system was a PYI R&D Marine 22B4. It had the original engine mounts in it.

The whole thing rattled and shook like an old Ford Model T running on one cylinder at anything under about 1100 rpm.

In looking at the whole setup the engine mounts were as hard as a rock and the rubber had cracked. It certainly looked like they needed to be replaced. In addition, after reading numerous posting on this forum, I thought while I was at it I would replace the damper plate with a new High Deflection plate.

Finally, I noticed that the muffler was not tied down firmly and was rattling around against the hull mounting.

So, I've replaced the engine mounts with Vetus K75's, the damper plate with a PYI R&D Marine High Deflection 22AM4 damper plate, and firmly secured the Muffler to the hull assuring that the hose leading to the engine was flexible enough to not transmit any significant vibration to the muffler, and hence to the hull.

I really wanted to add a flexible coupling to the propeller shaft as well but there just isn't enough room to get one in without modifying the propeller shaft and other stuff.

Boat goes back in the water end of the March and I can't wait to see how much of a difference this all made. If it is successful I'll post the results here. If not, I guess I'll post the results here anyway.

[jmcbraye@hotmail.com]

Many thanks to Jerry Ross for persisting and sending me your damper plate zip file. I worked with a mechanic last week following your very detailed and good instructions. I needed to have the transmission rebuilt because it was slipping in forward as well as replace the damper plate with the PYI RD 22AM4.

It took us three tries to raise the back of the engine. First two tries we forgot to remove the starboard motor mount bolt. Big mistake but no damage done. I have the following suggestions to ease the process and will post these on the C350 website.

- the prop shaft flange keyway extended into the the tranny flange approximately one half inch making it very difficult to pry the two flanges apart with the screwdriver. We were thinking we might have to cut it with a hacksaw but finally succeeded. Did not need to apply pressure to dripless shaft seal as it was not leaking.

- we put a piece of 2X4 under the carriage bolt but the bolt head kept digging into the board and slipping. Drilled a 1" diameter depression in a piece of 3/4 inch plywood and put at on top of the 2x4 to prevent slipping. Also used double nuts on top of the carriage bolt and vice grips on the nut under the port engine mounting flange to allow raising the engine with a socket wrench on top.

- rotated engine w 15/16" wrench to access damper plate cap screws. Old damper plate was still good with well over 1,000 hrs but replaced with RD22AM4 anyway based on C350 website recommendations.

- sea trial for rebuilt tranny and new damper plate all good. Still more engine vibration at low idle than I would like. Could be injector or fuel supply issue?

- mechanic took 16 hrs working hard and with my help. Difficult job w a few mistakes. Included HE removal and cleaning. Total cost ~$3,200.

Thanks again.

Jim McBrayer
S/V Escape
Hull #40

[BillBerner]

Yow!
That's a chunk o' change.

[dedgell]

On Blue Wing, the engine noise / rattle was very severe by the end of last season. I knew some repair was needed. The engine had 503 hours. Over the winter I read all of the posts in this thread, thank you to everyone who has shared their experiences.

I had the damper plate replaced with the PYI High Deflection. At the same time I bought the kit and replaced the bellows and seals on the PYI dripless shaft seal. Although I appreciate the step-by-step instructions, they made me realize that this job is well beyond my mechanical skills. I had the yard do the work.

This weekend we had our first sail. The difference under power is DRAMATIC. There is much less noise and vibration at idle in neutral, and at slow engine speeds in gear. The transmission shifts feels more direct as well. I did not realize how bad it had become. I encourage anyone with this issue to replace the damper plate.

David Edgell
S/v Blue Wing
C350#442

[Pete Bruzik]

Hi - YES!!! What a difference! Ours finally catastrophically failed at 2,700 hours - incredible difference in sound level!!! no more cement mixer! replaced with the PYI High deflection unit - job was beyond my skill set I bought parts mechanic installed for $375
Pete Bruzik - Pekabu 3 - #107 - 2003 - original owner

[kimmiya]

Well, the promised end of March launch ended up being the end of April, but the bottom line is that the replacement of the motor mounts and the damper plate that I described earlier have given the engine a new, and MUCH quieter, life. I couldn't be more pleased with the result and would recommend the conversion highly.

One minor thing with the new Vetus engine mounts is that you have to drill one new mounting hole in the fiberglass/aluminum bedding and tap it for each mount as the spacing of the holes is different than the originals. But it's not a big deal. Also, when you replace the engine mounts we found that a small shim to level the mount athwart ships really makes a difference. The original mounts are at a very slight angle to the engine bracket and end up "pre-torquing" the mount slightly. Seems it comes from the factory that way but I have no idea why.

[Monty]

these posts were in 2012 but I have the problem in 2022 in hull 418 with 1300 hours. I would appreciate it if anyone with updated info or detailed instructions on replacement would forward them to me. monty1221@icloud.com

[Flagmanmike]

I changed my damper plate this past Feb, by myself, mostly following the blog instructions. I offer a couple of "lessons learned". This is not an easy job. I grew up in a garage and found it a little challenging. While there is not a lot of room, ask for a helper, it'll go a lot better, and you might not get an A-Fib attack and spend two days in the hospital.

1. Use a foam cushion to lay on. It'll help prevent bruising .

2. To get better access, I removed the 3" piece of "floor" just behind the engine compartment and forward of the two large removable panels.

3. When using the 6" carriage bolts to raise the engine, I placed the rounded head of the bolt on a board with a shallow hole drilled into the surface. I used a 3/4" drill and drilled about 1/8" deep. This prevents the rounded heads from "walking" I did this the second time I tried to raise the engine, because the round head rolled on the board and "pinched" the bolt so I could not turn the nut. Not pretty.

4. Before removing the transmission, get two 4" long bolts of the same thread as the transmission bolts, I think mine were metric M10. Cut the heads off and deburr. Remove all the transmission bolts and just break the transmission free, do not remove yet. Screw the two 4" bolts into the top holes on either side of the transmission and slide the transmission off the splined shaft and it will be "caught" by the two 4" bolts. The bolts support the transmission and allow you to have more control of the situation. When reinstalling the transmission, put the 4" bolts in first and slide the transmission onto the bolts, making the alignment of the splined shaft much easier. I thank Jim Doyle at Tampa Sailing Squadron, Apollo Beach,FL, for this tip. A life saver.

5. When rotating the engine to get access to the damper plate bolts, have a helper jog the engine so you can just lay there and watch for the correct alignment.

Good luck.
Mike Cronin
FlagShip #314
Apollo Beach, FL

[wolfe10]

Excellent suggestions from Mike.

Observation on #4-- check with a fastener store-- they may have all tread in the correct size/thread pattern. Easier than cutting the head off the bolts.

4. Before removing the transmission, get two 4" long bolts of the same thread as the transmission bolts, I think mine were metric M10. Cut the heads off and deburr. Remove all the transmission bolts and just break the transmission free, do not remove yet. Screw the two 4" bolts into the top holes on either side of the transmission and slide the transmission off the splined shaft and it will be "caught" by the two 4" bolts. The bolts support the transmission and allow you to have more control of the situation. When reinstalling the transmission, put the 4" bolts in first and slide the transmission onto the bolts, making the alignment of the splined shaft much easier.

[Windhunter]

Yet another successful damper plate replacement thanks to the huge support on this board from Jerry, Leigh, Mike, and Brett!
I was getting lots of low rpm rattle and a big bang when shifting. Went with the PYI HD plate to cure the rattle and reduced idle RPM from 960 to 835 to minimized the shifting bump. The engine really gets rough below 900, but the tranny was getting hammered hard, so I'm happier with the engine vibrations than a torture transmission. I did mine in the water with help at critical points.

One more tip to add. I have a PSS and considered loosening the collar to slide the prop shaft back to seperated the coupling. I was just a little concerned that there would be leakage, especially since I didn't plan on completing the job in one afternoon. Instead, I was able to connect a small block and tackle to one of the coupler set screws and pull the couplers apart about 1/16". I hooked the other end of the tackle to a bolt I added to the shelf that muffler sits on. With the coupler plate on the transmission rotated so one of the notches pointed down, it was enough to get clearance during the lift and lowering. I used homemade guide pins for reinstalltion. I found 4" to be too long and caused interference with the couplers in my configuration. 3 1/2" worked better.

Special thanks to the suggestions of the ratcheting box end on the lift bolt. Also, foam pad and knee pads were true life savers for me!

[wolfe10]

Just want to point out that it is a good idea to change transmission fluid at every oil change. Do NOT overfill.

The transmissions do much better with clean fluid.

[Greg_D]

I am looking at purchasing a boat that has the vibration issue at low rpms. Goes away at about 1000rpm. The damper plate was replaced less than a year ago with one of the newer style units, but the problem persists. I'm guessing that motor mount replacement is next. How hard are those to replace? Any other things I should be looking at?

[wolfe10]

I am looking at purchasing a boat that has the vibration issue at low rpms. Goes away at about 1000rpm. The damper plate was replaced less than a year ago with one of the newer style units, but the problem persists. I'm guessing that motor mount replacement is next. How hard are those to replace? Any other things I should be looking at?

Some vibration at low idle speed is NORMAL.

Easy to bump up the idle when in Neutral (push in button and advance the throttle).

You do not want to raise the base idle speed, as that would hard time the transmission when shifting.

[russp]

Wow, this has been a long posting over a long period of time! I have had the shaft balanced, the motor aligned and mounts replaced, have replaced the damper plate with OEM part, but my engine/transmission/exhaust still rattles at idle, so I don't idle just as Brett suggests. If I drop back into neutral I just push the revs up to around 1100 and she is smooth as silk, and naturally have to drop back to low idle to get into gear.

It is a minor nuisance but not really an issue. From 1100 up the Universal is smooth, I can read the very fine lettering on the alternator with no problem so motor itself is barely vibrating. My major "clatter" at idle now comes from the flap valve at inlet to lift muffler, sooner or later I will change it out, but has been on the "to do" list for a while now.

If you want a smooth quiet transmission, my experience is you need a Z drive/saildrive, almost impossible to remove all imbalance and harmonics from a shaft drive.

[Olivia Mae]

Hmmm. Ours doesn't clatter or vibrate at low speed. FWIW, I used the R&D high deflection plate when I did ours. So, if everything is new, it could be I'm just less sensitive to any vibrations then you are. It also could be the prop you're running. I have a fixed 3 blade. Somee folding and feathering props have certain amounts of vibration inherent to them.

[Captain Kirk]

We had the same problem at low RPM - below 1100. We installed a high deflection damper about 400 hours ago and she idles nicely now at 900 -1000RPM.