B28 Cutlass bearing removal

[Yannis]

I thought I'd check my cutlass bearings and I'm glad I did.
The port rubber sleeve was detached from the copper shell which might have caused serious trouble if turned around inside the cutlass cylinder.
Whats more interesting is that while they removed the props with the traditional 3 legged extractor, they used this hydraulic pressurizing machine to remove the bearings without using a hammer.
And, as you have been recommending in a recent thread, I'm also happy to see I have teflon bushings instead of roller bearings!
Also, to my amazement, the rudders fell right down and removed, without having to dig a hole under each one, as was the case in '14 when I had replaced the bearings last.



https://imgur.com/6zw4CqW

https://imgur.com/nRIm0yB

https://imgur.com/3d2Ewbh

https://imgur.com/ntWPsiA

[Carl]

Yannis -

Check your alignment if your going through bearings that quick and or ripping the rubber free from the brass shell.

I love hydraulics...amazing stuff.

[Yannis]

Carl, you're right.

The guys told me that I’m out of alignment BUT the boat is now warped, I cannot do serious alignment on the blocks.
What do you recommend?

[Tony Meola]

Yannis

Once she is back in the water, let her sit for a day or two, then have them align the engines. They dont miive the shafts the adjustment is done through the engine supports.

[Yannis]

Thanks Tony.

[Carl]

Like Tony said, alignment needs to be finished in the water, after boat has sat for a couple days.

However on land is the time you do the rough alignment. Ideally the shaft runs perfectly parallel to the cutless bearing and is somewhat centered in the shaft log. This is checked visually by looking at the shaft in the bearing fore and aft . What you are looking for is pinched rubber and gaps between shaft and rubber.

Ideally the shaft sits on the bottom of the bearing in the 6:00 position with a very slight gap at 12:00, shaft rotates freely with shaft centered within the shaft log. If not, now is the time to make that happen.

You'll know which way to move based on how shaft sits within the cutless bearing. If the fore side of bearing has shaft pinching the rubber at the 6:00 position with a large gap at 12:00 and the aft portion has the rubber pinching on top with a spacer at 6:00 you know the motor needs to come up some. Same goes for left and right...all this and you need to make sure shaft is more or less in the middle of the shaft log. Then you move onto using feeler gauges, trying to get the faces of shaft and trans coupling parallel within specs given by your trans dealer...Usually .003...but as only rough now it can be out a little more...maybe .005 or .006.

[Yannis]

Carl,

The shafts, after the bearings have been removed, are sitting now as follows:

Port: Rear point of contact with strut, 7 o’clock
Stb: Rear point of contact with strut, 5 o’clock

We’ve discussed this briefly with the (very experienced) team and I said that the boat is exceptionally elevated at the bow, so that the water runs out freely from the stern valve, so the boat is now warped and twisted.
They said, hmmm ok, sounds logical.
This doesn't guarantee anything of course, but at least it means that these guys have seen similar twists in the past.
Now, I wonder how they’ll be able to fine tune all this in the water, as I have sincere doubts that all 8 nuts on the engine supports are unscrew-able. Especially those two rusted inner rear ones, one on each engine.
Yeah, I know, my friends told me to go fly a kite but I went out and bought a boat instead.

[Carl]

Yannis, you need to have the bearings installed to eyeball how shafts sits in place...or a pair of hard bushings/sleeves.

That or pull shafts and laser align or the old fashioned string method.

[Preston Burrows]

Yannis,

Just to add to others comments, and if not already, now's the time to check both shaft logs, shaft couplings and shaft stuffing boxes carefully with respect to their wear and maintenance.

[ In my experience, and to reassure you somewhat,usually if you simply replace the shafts cutlass bearings with the same/similar bearings and had no shaft alignment issues previously, you will find that things are ok, or close enough, once settled back in water...…on another note the cutlass bearings I use are, if I recall correctly, Johnson Duramax brand BEND, which always left me with a sense of unease name wise.... ]

[Carl]

Just to add to others comments, and if not already, now's the time to check both shaft logs, shaft couplings and shaft stuffing boxes carefully with respect to their wear and maintenance.

Great point

[ In my experience, and to reassure you somewhat,usually if you simply replace the shafts cutlass bearings with the same/similar bearings and had no shaft alignment issues previously, you will find that things are ok,

While true the alignment would be the same as before if you just changed the bearing...BUT my point is something is wearing and tearing up the bearing too quickly. Water with lots of sediment, fishing line, bad alignment...or any combination can wear a bearing prematurely. Four years is hardly enough running time to wear a bearing out the way he seems to use the boat.
Or another way of saying it is the the motors were aligned badly before the bearing was changed.

[Yannis]

Yep, as you say guys. Thanks for the advice, its more or less what I was thinking too.

The thing is all this requires days and people and....those two are in shortage lately. I think all shops will only be allowed to work for another few days.
And by the time the measures are withdrawn everybody will jump on the technicians and I foresee some problems.
Good luck and good health to all of us.

[Yannis]

This is the new bearing just before insertion.

https://imgur.com/cexlDv6

Carl,
I told the technicians how come I need new bearings after 6 years. They said 6 years is long overdue, normal substitution period is 3-4 years, otherwise the rubber hardens and breaks. Even if alignment is perfect and there is no wear on the rubber, still you need to replace every 3-4 years. Go figure.

[Carl]

They said 6 years is long overdue, normal substitution period is 3-4 years, otherwise the rubber hardens and breaks. Even if alignment is perfect and there is no wear on the rubber, still you need to replace every 3-4 years. Go figure.

I wonder if they have a different formulation on your side of the world.

We have been a factory direct dealer for 35 plus years, our only issues with the rubber turning hard was when petroleum products were used to install, running through an oil slick or they had a bad run. I got one of those bad runs in my last boat...rubber swelling and locked up on the shaft. Our commercial guys go through bearing every few years, but that's due to boats always being used and in high sediment conditions.
OK, one guy that uses his boat like nobody I know, on a whim he'll run his boat to Nova Scotia to fish for giants, then to the Bahamas for Bone fish and on his way down fish a couple tournaments, his boats always on the move and he's about the only guy I saw every couple years for worn out bearings...till we went Thordon.

3-4 years is hardly broken in. I've heard at 500hours to change them...but I've seen them run much longer. Its really as long as there is only the slightest bit of shaft movements they are still good. Now a shaft that is not aligned constantly rubs and wears the bearing instead of the shaft riding on the water between shaft and rubber as its designed to do.

[Yannis]

Carl,

The examples you are referring to have a common element. That of usage time (hours) and wear and tear from hard usage, from imperfect alignment or from external hardships, like murky waters, fishing lines etc. I agree with all of them.

What I’ m saying is that regardless of these conditions of use, there is a factor of time. The rubber is prone to degradation as a result of time. Irrespective of usage. As I said, I was told by my guys that their life expectancy is 3-4 years, so 6 years in my case was long overdue, and deserving a replacement.

I have no idea if we have a different chemical composition in the rubber, although I doubt it.
Is it perhaps the salinity of the mediterranean? Is it the important temperature variations? Is it the time boats spend outside on the hard? Is it a combination of all these? I cannot tell. It’s not all that important anyway, as it’s just another prelaunch task to undertake every now and then.

There is a serious volume of yachting, but also a serious volume of shipping in Piraeus. All these shops deal with hundreds if not thousands of local and international clients so they must be experienced, otherwise they'd be out of business, and you know that in this business the word of mouth is very important. So I trust these guys.
What bothers me though is why there is such a difference between what they say and what you're saying. I wish I had the answer but I don't.

[Bill Fuller]

Yannis,

I feel I need to say something on this subject. You may remember that I have essentially the same setup as you.
My cutlass bearings were installed May of 2000, that's 20 years. The boats has 6,645 hours. The cutlass bearings are still perfect!
Obviously, my shafts were aligned perfectly from day one. I have had to replace torsional dampers on both motors and was extremely careful when doing the re-alignment. I do all of my own work. Unfortunately I do not remember the brand of cutlass bearing that was used when I repowered back in 2000.

Just saying. They can last a very long time.

Bill

[Yannis]

Hi Bill,

I hear you.
I tell you what. I just changed my bearings and I noticed imperfections in the alignment, mostly on the port shaft. I will go like this for this season and by October I plan to pull the engines for some tlc, but also for doing the beds, as well as reinforce the strut backing plates and, this is important also, make sure that I seal all holes in the bottom part of the bulkhead so as to keep water out permanently. I cannot stand anymore the situation, whereby whenever I rinse the deck I find two buckets of water in the cabin bilge. While I’m at it, I will make sure that alignment is done right and, perhaps change my shafts.
They are 1 1/4”, I suspect they are a bit too thin for my diesels. If anyone can comment on this it would be helpful.

[Bill Fuller]

Yannis
For sure glass in the holes that allow water to enter the cabin area.
And add a third bilge pump next to that bulkhead.
One of the best things I ever did for the boat.
Keeps the cabin completely dry. But there are 2 more holes pretty much directly under the stringers.
Leave these open. Then in case of an emergency, pump quits, gets over whelmed etc. water will go into the cabin and be removed by the forward pump.
You may know, that Bertram started building the B28 this way in about 1978.
Good luck, have fun, stay safe.
Bill

[Yannis]

Bill,

I have a third pump by the galley, where is the lowest point. I have three hatches on the cabin sole so everything is accessible.

The stringer holes are complex because right where they go under the bulkhead they also have a void underneath for water above the stringer to flow down all the way to the cabin bilge. I will keep that function but I will close their access to the engine room because that’s where water comes in from. And, of course, there are tens of other holes, for the head, the shower, the water intake, and many more. All these hoses have to be moved up a bit so that water doesn't flow in. I have to rethink all the water supply system, but then again, this is why I love my boat, it never lets you get bored!

[Tooeez]

Yannis, I respect that you trust your guys, but remember, if you ask a guy that makes his living selling ice what the solution to any problem you have is the odds are the answer is going to be buy some ice.
I have replaced both the factory original bearings on my 1979 28: the port side in 2001 at 2300 hours when I replaced the shaft (the shaft had more wear than the bearing), and the starboard in 2015 at 3600 total hours. The rubber on that one, after 36 years, was fine--not degraded in any way. It really didn't need changing, just had the slightest play, but I was doing some other work under the boat and thought I might as well swap it out.

[Yannis]

Tooeez,

Yep, you're right, I thought about this one too, however trustworthy, these guys want to make a living...
And since you, and others here, insist on how long these rubbers can live, I’m starting to have some doubts too.
Anyway, I’ll live with it until next year when I’m gonna pull everything out and make things right.

PS: when the technicians were tightening the prop nut with this huge wrench, it must have been close to 70cm long, they also used an extension tube for more torque that was another half meter, I saw the strut swaying to the direction of the force applied. That proved how much more beefing up the strut backing plate requires...an issue that will not go unnoticed when time comes.

[Carl]

PS: when the technicians were tightening the prop nut with this huge wrench, it must have been close to 70cm long, they also used an extension tube for more torque that was another half meter, I saw the strut swaying to the direction of the force applied. That proved how much more beefing up the strut backing plate requires...an issue that will not go unnoticed when time comes.

Could also be a sign the shaft nuts are being over tightened...



...by alot.

[Tony Meola]

Yannis


Next time you ask them to put the props on, use my father's favorite expression when you ask them to do it, tell them not to screw the eyeballs out of them.

Every time someone other than him was putting spark plugs in a car, he would always walk by and say that to the person. It holds true for everything we tighten.

27 inch wrench should give him enough leverage to tighten those nuts without twisting the struts.

[Yannis]

Tony and Carl,

Perhaps this task with the prop nut should be done with a dynamometer?

As for the spark plug, I was in high school when I bought with my two buddies a used 50 cc Honda CB. One third each.
Because the other two couldn't even imagine telling their parents about it, we were keeping it in our home, not that my dad approved, but I told him that it only belonged to the other two, so it passed for a while.
One day I tried to change the plug and twisted it so tight that it broke inside the cylinder.
I took it to the mechanic, by pushing it of course, and he managed to take out the threaded metal part as well as the pieces of porcelain that had fallen into the cylinder...
From then on, until today, whenever I see someone tightening a plug I always advise them what your dad used to say. Tighten by hand and then 1/2 a turn with a wrench.
Keep safe, stay at home.