Catalina 350 International Association

3 Signs It's Time for a New Cutless Bearing

1.) You hear rumbling or vibration that slowly increases over time.

2.) If the shaft is centered in and parallel with the bearing, any movement in the shaft when it's lifted indicates wear. (Note: An improperly aligned shaft could bind, masking the wear.)

3.) Measure the actual gap between the shaft and bearing surface. A 1.25-inch shaft should have clearances between .003 and .007 inches.

As told by Steve D'Antonio in Cruising World article January 20, 2010

I finally got around to finalizing my damper replacement project. It's taken longer than anticipated because I am doing several other maintenance/repair tasks at the same time, and of course, other issues sometimes call for my attention.

Today, I finally finished re-installing the cleaned out & painted heat exchanger and was able to replace the coolant and fire up the engine for the first time since replacing the damper. I must say I was impressed. The old damper showed no signs of disintegration as previous photos for others have shown, but we have always had a 'clunking' that sound a lot like a farm tractor up to around 1700 RPM. I have been concerned that after all this work and cost, that I would see no change. I installed the PYI 'high deflection' damper part number #22AM4. When I first put it in gear at the dock, there was a single clunk then just the sound of the engine at idle. When I took it our of gear, there was virtually no change in sound. I was shocked at how smooth the boat was in gear at any RPM, considering I saw no signs of degradation on the old damper. The engine shows no signs of shaking and vibrating as it previously did. I suspect that I will now be able to lower my idle RPM back to around 950 (presently about 1050-1000 to keep the vibrations tolerable).

After running for nearly an hour and making sure that nothing was leaking, the only problem I had was that I could not stop the engine. Pulling the stop handle just created a struggling sound from the engine, but it would not stop. I finally traced the problem to an improperly adjusted cable that wasn't allowing the stop mechanism full travel.

Now all I have left to do this winter is bleed the air out of the coolant, change the fuel filters, and oil and oil filters, clean up the mess and get ready for the spring cruising season.

Gary & Janet
Bravo!
I hope all fellow owners learn and benefit from your success.

Leigh Weiss Brisa #155

The ice is finally off Lake Michigan so we launched Dock Hoilday (#359) yesterday and tried out the new PYI high defection damper plate I installed last week. WOW, what a difference. I can hardly hear the transmission while idling in gear. Thanks to all for the postings and opinions on how to tackle this project. It took about 4 hours to take it apart and 2 hours to put it back together. Best off all, I'm much more familiar with how things work behind the curtain!

"Instead of a thrust bearing, Hurth uses a thrust washer. This washer wears every time the shaft goes around. It's a guaranteed failure item."

I'm doing the Damper Plate repair. My boat has all the symptoms.

While the transmission is out, it this thrust washer replacement a reasonable maintenance item? Is it a couple of bolts and a $50 part, or does it need to be sent out to a repair facility (i.e., special tools, knowledge, etc.)

While the transmission is out, it this thrust washer replacement a reasonable maintenance item? Is it a couple of bolts and a $50 part, or does it need to be sent out to a repair facility (i.e., special tools, knowledge, etc.)

Nope, this requires a full teardown of the transmission - it's actually the very last part to come out, and first to go in. The part itself is only about $25.00 or so, but you have other items to replace on your way in and out.
Al

Hi Al,

Thanks for the quick response. Were you able to get your hands on the service manual? Did you perform the tear down and part replacement? Maybe you can start a new thread on your experiences? Pictures? It would be good to hear about it. Parts, skills, tools required. Some of these tasks are less intimidating when we know in advance what we are getting into. Mine is not broke and I replace the fluid every year. If it is a major PIA, I guess I can wait till it breaks.

Thanks,

Mark

Mark and all who want to know!
I found the service manual for the transmission on line as a PDF file. If you need it I will send it along . Just drop me a note at
weiss@rowan.edu
When I change the oil I take a sample of the oil and smear it on a glass surface and then examine it for the tell tail brass flakes from a worn thrust washer. So far so good!!!

I just finished installing the damper place. A couple of notes.

PYI changed the part number from a 22AA4 to a 22AM4. Three months ago when I bought it, it was $225.00.

I found using a reversible stubby flex head ratchet handy for running those nuts up. I never owned stubby wrenches before, but they were useful on this job. It was great for the cramped space. Also, no reason to try and bump the engine with the starter, you can bar it over with a 15/16" wrench.
I wasn't real keen on the carriage bolts. They kept moving around. Maybe a regular bolt with a hex head and piece of rubber underneath? I also used a prybar on the motor mount to push the feet back so the engine would drop over the stud when reassembling. That made it easier.

Thanks for all the info. I would not have had a clue otherwise. Thanks!!!

(wow. those are big pictures. I'll remember to make them smaller next time.)

Can any of the folks that replaced the damper confirm that the ZF (Hurth) transmission on the 350 is the model ZF15MA with the 8 deg deviation and not not the ZF15M? According to the nameplate it is the former. After 6 transmission failures it's coming out for good . The damper plate is in very good condition and there was no chatter before the latest refusal to go into forward. No doubt the the trusty thrust washer had a hand in it but rebuilding again seems illogical.
Although Universal have stated the alternate transmission supplier can be used with some shimming of the engine I can't how you could align the coupling. The dimensions of the PRM are very CLOSE and the spline is the same but not seeing how it would work.
This means installing another ZF Hurth...............

Duncan,

I wrote down the transmission information when I replaced the damper plate. I show our transmission to be:
Hurth ZF 15MA (HBW 150A) P/N 3306001004 S/N 41625.

I'm not sure about the '2' in the S/N.

Of course different 350 models may have different transmissions. We are hull #422, and have about 850 hours on the engine. Replaced the damper plate at 759 hours.

So far so good.

My 2003 C350 hull # 111 has about 675 hours on the engine and has started to give me problems when under way by not always shifting smoothly, sometimes being noisy with vibrations and twice, failing to go in reverse as I was coming back to my slip. When tied to the dock, it shifts smoothly with no noise into both forward and reverse even at rpm's well above idle. I had a friend look at the linkages while I shifted and all seems tight. I have a mechanic coming to look at it Wednesday morning. Could this be the damper plate or hopefully something simpler. I have read the excellent write up with photos and have concluded that replacing the damper plate in way above my mechanical skills. Any comments are welcome.
Thanks,
Richard
Three Sheets
Montvale, NJ

Fortunately the noise, vibration and occasional failure to go into reverse was not because of the damper plate or transmission. It was caused by the Auto Prop not always turning on it's ball bearings. They obviously wear over time and need to be replaced. After a sea trial, my mechanic concluded that we haul the boat and remove the prop. It was replaced with the original standard 2 blade solid prop and is now running smoothly. I will be returning the Auto Prop to AB Marine for refurbishing. Lesson learned: Take nothing for granted and have the prop removed and checked at least every 4-5-years.
Richard
Three Sheets
C350 # 111

Did you mean "3 blade prop". The factory supplied prop is a 3 blade model.

Richard Thabit wrote: It was replaced with the original standard 2 blade solid prop and is now running smoothly.
Richard
Three Sheets
C350 # 111

It is a 2 blade prop. 15RH10. I took delivery in May, 2003 and the Auto Prop was installed as part of commissioning. The 2 blade did not see water until last week. I believe that Catalina made at least 2 prop changes to the 350 over the years. The Auto Prop is much more efficient. In less than 2 hours with the 2 blade I see great differences in performance so I sent the Auto Prop back to AB marine for an estimate for refurbishing.

So what is the down side of not replacing?

I have some noise and some "dust" but the transmission is shifting properly and everything else seems to work.

Great write up!

Thanks

The down side might be "boat no go"
How many hours do you have on the engine?
Which engine do you have?

I think that some boats with the Universal engine had a problem with around 500-1000 hours some much less.
Mine chattered from the start, hence the replacement.
I guess I look at damper plate replacement as a PM, but if you have no rattles at low speed and low engine hours, then wait.

Thanks for the excellent write up. I'm fairly sure I have a similar problem as I've located some brown granules in the bilge. I also have a bit of black pepper looking stuff mixed in with a few drops of oil.
We have been in rough seas over the past month and we've pushed S/V Soixante hard but also idled in some difficult sea ways. We also have logged about 200 hours between trying to get to the Abaco Islands and Racing in St. Augustine.

I did call ZF and they confirmed that not replacing the damper plate would result in not being able to shift into gear.
Fortunately, I'm just at the beginning of this problem but it's a must fix before our next long journey.

In any event, thanks again.

Yup: it's the damper plate. Mechanic just left and I'm ordering the parts.

I had also had overfilled the transfluid and we changed that out and corrected the level while he was here.

I'm going with the PYI damper plate upgraded version RD 22AM4.

Below is the e mail from them about upgraded plates (I got permission before publishing comments)

Thanks to all for your input….Jamie
Soixante
Sail #444

"Thank you for sending in your inquiry regarding R&D. Part number 44624 is
> reference our plate number RD-22B4, $180. This is the stock plate that
> Westerbeke uses. The RD-22B4 uses a "loop" element inside that gives around
> 3 degrees of deflection.

The RD-22AM-4, $232 is the upgraded plate. The
> element is a "high deflection" element that gives up to 33 degrees of
> deflection. This is a much better plate at low rpms. It is usually used in
> work boat applications or engines that just rattle a lot a low rpms. Most
> customers with Westerbekes have been going with the RD-22AM-4 when they are
> ready to replace their old plate. "

Our engine sounded particularly rough this season so Damper Plate replacement seemed in order. It was 10 years old. Had ordered PYI damper plate RD22-A-4 two years ago just in case. Took 5 hours to do. No need to remove the heat exchanger, I started to and it was hard to get the bolts back in as the brackets are spring loaded.
I did not have the proper socket to loosen the nuts on the top of the motor mounts (larger than 7/8 inches), so in the end I removed the transmission shift cable, and removed 8 of the engine mount bolts at the base and just pulled the engine forward a few inches. I did not have to remove the throttle cable. I used a 2 by 4 to lift the engine, it was not as heavy as I was expecting. I am guessing it weighs around 300 pounds. I just put some scrap wood under the rear engine mounts to hold it up a bit. Also I was not able to remove the adapter from the prop shaft and slide it backwards, so pulling the engine forward would saves the hassle of loosening this. As mentioned previously the port bottom bolt on the transmission must be removed last, and the bolt above it second last. These nuts are very strange as you can't get a wrench on the bottom bolt if the one above it is loose. I used a large wrench to rotate the engine in order to get at the damper plate nuts (two are visible at a time). To do this job some bolts seem to be metric, and others inches, most of the bolts were 17 mm on the transmission. Photos are attached below.
The engine is so quiet now, its great.

Jan #303