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Shaft & Motor Mounts / The Snowball Effect

Maine Sail

Member III
I get lots of comments on my site to the effect that I make these jobs look too easy. They are easy.;) It does not mean they don't get frustrating, tedious and maddening though. Yes, we all face the same obstacles when working on sail boats and there is no way to get around that.

Thinks of this post is reminder of how boat jobs often go awry with one problem leading to, or unmasking, yet another. I call it the SNOWBALL EFFECT.:cussing:

This job was to be a simple shaft, cutlass, coupling & prop replacement but oh how things change when you get going. The boat, a mid eighties Ericson 34, has relatively low engine hours for her age but exhibited a very high level of vibration.

After I pressed out the cutlass bearing it became very apparent just how badly the vessel was misaligned.

Not only was the engine sitting far to low in the shaft log, and the shaft was thumping it when the engine was in gear, but it was also not passing through either the shaft log or the cutlass even close to parallel. The minute the cutlass came out the shaft sprang up and pressed into the top of the strut. While boats can lose some alignment out of water it is usually measured in the order of thousandths of an inch when measured at the shaft coupling. Our CS looses about .001" from in water to out in terms of alignment and she has a significantly longer shaft. The E-34 has a fairly short shaft, approx 46", and robust engine bed area so flex was clearly not causing this level of alignment issue. Read on and you'll find out the real reason this motor was so badly aligned.
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When we got the new shaft in place I wanted to adjust the engine first to do a rough alignment. Ericson, in all their infinite wisdom, chose a three point motor mount system for the Universal M-25 diesel. Three mounts is not the norm in boat building and almost all engine manufacturers ship engines with four mounts, generally with good reason.

The minute I put a wrench to the front mount in order to adjust it and thus drop the shaft from impinging on the top of the strut, the mount stud simply began to spin in the mount.:mad: In the marine environment studs can get rusty, or in this case, the threads also get mashed and the stud with this type of motor mount design breaks free from the rubber it was molded into. These mounts are a bad design for boats, in my humble opinion and experience with them. It was clear quite quickly the boat needed at least one new mount but I suggested to Chris that ordering three new ones was ultimately the best choice and gave him the part numbers.
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One thing I often see that destroys motor mounts prematurely is the lack of properly tightening the stud nuts that clamp the motor mount bracket. If these nuts are allowed to become loose the motor mount bracket or bell housing ears will vibrate over the threads and wear them away to nothing. All three of the mounts on this Ericson 34 had badly worn threads. Worn threads will prevent any future re-alignment and require new mounts whether the rubber is ready to be replaced or not. One of the mounts was perhaps still in operable condition had the threads not been destroyed by the nuts coming loose. The other two were toast, one snapped and both spinning in the rubber.

In order to replace these mounts with a different model or brand would have entailed a far more costly and time consuming job due to differing bolt centers for the mounts. I have also had bad experiences with substituting aftermarket mounts. Due to the three point design of the Ericson motor configuration is likely dependent on the rather stiff lateral design of these mounts and the factory Westerbeke mounts are likely going to allow to much torque twist if only three were used. It was decided, though not very happily, to re-place these mounts with the same brand & model.:doh:
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Yes, this simple shaft & cutlass replacement turned into a total comedy of errors. This was the starboard rear mount. It had been broken for quite some time as evidenced by the mushrooming of the sheared stud. With one failed mount, in a three point Ericson design you are now left with just two mounts holding a 350+ pound engine in place, scary! If there had been four mounts and one broke not as big a deal, you'd be back to what Ericson used every day, but with just three motor mounts...well... it is what it is.:rolleyes:
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This was the sheared stud. It had obviously been broken for a while as evidenced by the mushrooming of the stud. Broken mounts are not all that uncommon in Maine as we have lots of lobster traps to snag a motor and stall it by stopping the prop. Sometimes the shaft bends, sometimes the prop, sometimes the gear box fails and sometimes a mount fails. I can't say what caused this mount to shear but I can say having only two mounts left, when one fails, is a little scary.
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The red mount on the right is an older style Westerbeke/Universal engines factory motor mount. They are well designed, robust and do a very good job of isolating vibrations despite their rather expensive price tag. That red one has 2782 hours on it and the two failed mounts to the left are low hour mounts that had already been replaced once before. There are features of the Westerbeke/Universal mount that make them well worth the money;

1) You can not twist the stud inside the mount because it is welded directly to the mount cap.
2) The feet are encapsulated in molded rubber helping minimize noise and vibration transmission.
3) The metal cap prevents engine oils from eating away at the rubber by shielding it.

In short I am not a big fan of the two mounts to the left and I have seen the failures repeated prematurely a number of times. To do this job right would be very expensive. My ideal installation for this boat would be a four point mounting system and factory Universal/Westerbeke mounts.
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I'm not kidding, and yes it just keeps getting better, or worse depending upon how you look at it.;) This picture is one darn good reason why I detest "Ideal" style or perforated hose clamps. This was the hose clamp for the stuffing box hose. Two out of the four literally fell apart the minute I touched the screw driver to them. Yes, scary!!

Because the perforations make the center of the clamp softer than the edges, due to the removed metal for the perforations, they can bend upwards and away from the screw threads over time. The screw on this one literally fell out of the holder and yes, they were marked "all stainless". These hose clamps were keeping this boat afloat and thank God there were four!

Please try and use non-perforated hose clamps for your below water connections. I prefer the AWAB brand and have never once had one fail and I have seen buckets full of the perforated style fail.
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Whew, finally getting to the actual replacement of the mounts which is actually quite easy. To make this task easier I use my favorite scissor jack. This jack came from a Honda CRX I owned in high school. I loved it so much I kept it when I sold the car. This little jack folds to about 2" tall making it easy to slide under even the lowest motors. These can be found in junk yards and will be the best $5.00 you ever spent.

There was yet one more problem with this installation the stud on this front mount winds up behind the lower crank shaft pulley. When the boat is put in gear and the motor moves slightly forward under load the studs threads grind on the back of the pulley. In order to prevent this the stud needs to be cut shorter to clear the pulley once the engine is in alignment.

When jacking a motor be sure that any hoses, refrigeration belts or other items that can impede the raising of the motor are disconnected. You'll also want to loosen but not totally remove the top nuts on the other mounts to facilitate the motor being lifted enough to get the mount out. Removing the old mount and sliding this new one in place took all of about 10 minutes.
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This engine room has very tight access on the starboard side. In order to remove the motor mount lag bolts I used multiple socket extensions, which made this a quicker and easier job.
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For a 34 foot sailboat this engine room is quite loaded with gear. She has Sea Frost engine driven refrigeration, fuel filters, water heater hoses, upgraded alternator and many other non-standard features that make working in there tight. The small jack is critical on engines like this for replacing motor mounts.
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The camera angle makes this area look a lot more roomy than it really is. The scissor jack fits nicely between the engine bed stringer and the engine and is lifting in-board of the motor mount hole but using the motor mount bracket to jack the engine. This is a good illustration of why this little jack has stayed in my tool quiver since 1985..
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Here is another shot of the scissor jack. I collapsed it entirely and slid it in through the transmission opening in the bulkhead. You need to be careful and use mirrors to make sure you are not jacking on the oil pan or any sending units, hoses or fragile brackets. Oil pans can be used on small engines but I would advise using a block of wood to spread the load. If your oil pan is rusty please do not use it or you may punch through. If possible always use the mount or another strongly supported area of the engine.

Lifting one corner of an engine is not a lot of weight. The weight is so little that I can usually twist the jack screw by hand with no extensions or tools. With the other mounts loose it is very easy to lift one out. If you can get a good jacking angle and find enough support you can lift in the center and raise the front or rear and do two front or rear mounts at the same time.
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Yes, believe it or not I discovered yet another problem. Once all the new mounts were in place I began to do a rough alignment of the motor to the shaft, cutlass & shaft log.

For some reason the I could get close but she just kept popping back out of alignment no matter how I moved the engine. After 20 minutes of mucking with her we realized why the engine was so low to begin with. A previous owner had replaced the exhaust elbow, a whole other set of problems, and made the nipple between the manifold and the exhaust elbow to darn long.

To correct for this mishap they Mickey Moused it by simply lowering the engine so the exhaust outlet cleared the bulkhead. This fixed the exhaust issue but caused many more as you'll see below.
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As I said this entire project has been a comedy of errors. Either the previous owner who did all this work was a really bad DIY guy or he hired the worst mechanics on the planet. There was no reason for this exhaust elbow to be tilted off center other than the fact that the installer refused to use pipe dope to mate the NPT fittings together.

It probably bound up and refused to turn anymore so they just left it tilted off center. Due to this laziness, or lack of understanding, it caused the exhaust elbow to chafe, vibrate, dent and make a career ending thin spot in the heat exchanger. Cha-ching $$$$ more unnecessary expense for Chris. Had someone done this job right to begin with he would likely not have needed a new shaft cutlass, motor mounts, heat exchanger etc. etc. etc...

This manifold will fit and will clear the bulkhead & heat exchanger when installed correctly, it was not.
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As mentioned the exhaust elbow was a disaster of an installation. Who ever did this install knew nothing about thread sealants or pipe dope. It took hours of soaking with PB Blaster, some heat, a massive bench vise and a 3.5 foot 1 1/4" black iron pipe as added leverage to an 18" Rigid pipe wrench to break these fittings apart. Due to the improper installation of these threaded fittings they had been leaking early on and thus rusted together as strong as I have seen in a long time. PB Blaster is great but when you are dealing with sealing threads, such as NPT, that are meant to keep fluids out, they also tend to keep most of the PB Blaster out too.

This exhaust flange fitting is a $90.00 part from Universal so I clearly wanted to save it for the owner.
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So after many hours of soaking and a very long pipe on the end of a very robust pipe wrench the nipple finally gave up its hold. The force needed to remove it from the exhaust flange crushed and made it oval.
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This is what my 3.5 foot black iron pipe looked like after I broke the stuck fittings free. I have not done the calculation on how much force I applied but all my 200+ pounds were going into that leverage pipe and the fitting was over 4.5 feet away away from the end of the pipe.
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Chris was already into this job for a new shaft, coupling, cutlass bearing, three motor mounts, Ultra-X packing, stuffing box hose, four AWAB clamps, a heat exchanger and various nuts bolts and hardware. I really did not want to have him absorb the cost of a new exhaust elbow and flange on top of all this for just for a few stuck fittings. This would have been about $300.00 worth of additional parts but I was able to clean, paint and we'll re-use them.
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I was able to take nearly 2" out of length out of the nipple between the exhaust flange and the exhaust elbow. This will allow the elbow to no longer hit the bulkhead and to also clear the new heat exchanger. I used a street elbow for water injection which allowed the assembly to be shortened.

This exhaust elbow is not a Universal Engines genuine part hence the reducing bushing from 1 1/2" to 1 1/4". Gotta love the snowballing effect!

The motor mounts were the easy part of this job. It is all the little things you find along the way that make the job take longer and really get frustrating. for example getting the exhaust elbow off the engine required the engine to be completely lifted off the mounts and moved forward. We used a 4:1 Harken block & tackle to a beam across the companionway for this. This little extra step added almost an hour to the job alone.


So a simple shaft & cutlass replacement led to; three new motor mounts all failed, removal & reconfiguration of the exhaust elbow, a new heat exchanger, failed hose clamps, engine antifreeze flush & fill and more. This is a much more typical job than it would seem and this sort of snowballing effect happens quite often with boats. See, it's not always easy...
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So far this job has been an excellent example of the SNOWBALL EFFECT and it's not even done yet!!;);)

P.S. Next time you are not DIYing your own boat repairs and you are unhappy with the labor bill from the yard come back and re-read this post.;) Sometimes no amount of planning ahead alerts you to the hidden problems that lie waiting.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Real nice article, and thanks for sharing.
:rolleyes:

Did you have enough band aids on hand for your knuckles?

It always seems like you have to repair your way through a growing project list just to finally get back to the project that you started with!

(If you have read my thread about replacing the holding tank and... rerouting all the hoses... and etc, etc... yup - been there and done that.)
:p

Edit:
Adding a reference to some past threads on this topic:
http://www.ericsonyachts.org/infoexchange/showthread.php?t=3997&referrerid=28
http://www.ericsonyachts.org/infoexchange/showthread.php?t=8164&referrerid=28
http://www.ericsonyachts.org/infoexchange/showthread.php?t=3681&referrerid=28

Regards,
Loren
 
Last edited:

mherrcat

Contributing Partner
I am going to be removing my exhaust manifold to replace the alternator bracket. What paint did you use on the exhaust flange and elbow?
 

rwthomas1

Sustaining Partner
A typical project as far as I'm concerned. No matter what I touch, be it boat, car or house, etc. almost every project progresses as that one did. Nice job though! RT
 

escapade

Inactive Member
My wife usually refers to these types of projects as "Another home project gone wrong". Having replaced the motormounts on our E34 (as well as the cabin sole, transmission, added 3 1/2 feet to mast, bottom, etc) it is comforting to know it's not just me. BTW, watch the screen in your air filter. Ours wore through from vibration a round piece which then traveled through the intake and held the intake valve open (as we where leaving on vacation!). This required removing the cylinder head to remove. While apart I did a valve job, new seals, etc. Gasket set was $90 from Kobota, $270 from Universal/Westerbeke.
My heat exchanger also had a hole worn through from improper installation, but I was able to solder it up rather than replace. Sounds like these ham-fisted mechanics exist all over.
Great article with good pictures. Don't give up!
Bud
 

Lucky Dog

Member III
Reminds me of friend who tighten the toilet bolt, cracked the porcelain, after removing the toilet he discovered termites and rotting plumbing. 17,000 dollars later the seat didn't rock.
 

franson08

Junior Member
Excessive Vibration when motoring

I recently purchased an Ericson 34-200 and the surveyor identified excessive vibration. A new 2-blade Maxprop feathering propeller was installed about two months ago by the previous owner and it feathers easily. According to the marine surveyor:

The cause of the vibration when motoring is unclear and the vibration increases with rpms. The vibration isn't present when the transmission is out of gear No sign of a significant bend could be detected at the alley by rotating the shaft against the tip of a knife. The alighment has reportably been verified.

The suryeor recommends removing the shaft and verifying that it is true or replaced. Riasing the engine on its mounts should considered when the alignment is done. The surveyer came highly recommended and is well respected in his field.

Do you have any expereience with similar situations and/or advise for the new and inexpereinced boat owner?

Thanks,:egrin:
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Given the vintage of your E-34 (late 80's?) I would guess that it is time to put in some new mounts.
When our mounts were replaced we found that the rubber on one of the rear ones had deteriorated (invisibly) to where there was metal on metal.
Since the rubber breaks down due to time just as much as to use, you might want to consider an arbitrary replacement.

I wonder if the p.o. had the cutlass bearing replaced while the boat was out for the new prop?

And, it the FWIW dept.... The owner of the oldest prop and shaft shop in our area once told me that they always true up a new shaft after it comes off the storage rack, when sold and about to be installed -- he said that the ss shafting sometimes would take a very slight curve from resting on the pegs on the rack. As the saying goes: "Who knew!" :nerd:

From Maine's description, it is best to start at the prop and verify your way forward, piece by piece and step by step.
:rolleyes:

Dealing with Deferred Maintenance is no fun at all. Hang in there. We've all had to deal with repairing problems left to us by prior owners (p.o.).

Best,
Loren
 
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