Strut alignment

[Witzend]

After successfully replacing my cutlass bearing (slid in with relative ease after thoroughly giving the strut a brush job with the drill and putting the bearing in the snow and warming up the strut with a torch), it is now quite apparent that the strut is way out of alignment and this was the real reason for the wear on the original bearing. The settling of the motor due to worn mounts contributed, but most of the problem lies in the incorrect alignment of the strut. How much of a PITA is it to align the strut? Looks like it is glassed in to me. When I inseart the shaft using soapy water it is crushing the top aft of the bearing and the bottom forward and is so tight I can barely turn the shaft by hand. This all while keeping the shaft at the top of the shaft tube in an effort to relieve the pressure.

BTW the Moris "BlackFish" is advertized with a 1/32" wall thickness, and it actually is 3/64" So it seem both manufactures have their specs incorrect. I can live with the 3/64" (.046) but not the .07 that the Duramax "Back" was. The Duramax literally had no rubber in it.

So far I'm very disappointed with the quality of this C310. I can't believe that the factory shipped this boat with the strut so far out. Also the mess I have had with the use of the R&D damper plate which failed after 500 hours and the damaged it caused to input spline of the transmission shaft. I'm F!@#$%ing pissed and will never buy another Catalina or production boat again!!! No quality controll!! Are you listening Catalina!!!

I will try to take a pic next time I'm at the boat.

RE:
http://forums.catalina.sailboatowners.com/showthread.php?t=114418

http://forums.catalina.sailboatowners.com/showthread.php?p=680614#post680614

http://forums.catalina.sailboatowners.com/showthread.php?t=113844

 

[Maine Sail]

Witz,

Yours is not the only C-310 to suffer this problem. A guy in my town owns what I believe is a 2001 or 2002 310 named, I think, Annie O'day.

His strut was re-aligned by Handy Boat in Falmouth, ME under warranty. I should have snapped some photos because the strut bolts are really, deep up in the hull and it is filled with lots of thickened glass. It took the yard quite a while to fix this.

My 2005 was spot on so perhaps they had a problem with the earlier ones..? I would not describe this as an easy task on the 310 but one that can certainly be done, despite how tedious it is..

 

[Witzend]

Thanks for the quick response Maine!! What are the chances that Catalina will honor this? I doubt it after 9 years. Might it be easier to raise the shaft tube and engine? In fact the shaft hits the inside end of the through hull tube while only being in the center on the outside of the tube, so it would appear that the tube is cocked forward end down as well.

 

[paulj]

Witzend
I'm happy you are taking the leed on this project.
If your boat is out of water it would be nice to have pictures of prop strut and shaft entering and exiting log shaft before fixing.
I think the final adjustments to align the shaft to the engine should be when the boat is in the water, mast is tuned and engine not running.



Where is it binding in this sketch?


paulj :troll:

 

[Roger Long]

If Catalina won't fix this for you and the strut is not aligned with the shaft tube, there is a way to repair it that will probably be cheaper and leave you with a better and more durable bearing than trying to realign the strut. You'll pick up a tiny bit of horsepower as well.

Let me know if you're going to have to do it entirely with your boat bucks.

 

[Don Crowther]

Roger
I'm not sure what your talking about.
Are you talking about Paulj's attachment? Or do you have another way to align the shaft?
Don

 

[Ed Schenck]

Agree Don, it's almost like Roger quit in the middle of a thought there. Could he be making reference to the idea of moving the engine and shaft tube? Hope not.

Really should not be that difficult to grind out some fiberglass and then glass in a properly angled shim. That part of the boat is really thick and solid, lots to work with.

 

[Roger Long]

Or do you have another way to align the shaft?

I'm talking about what to do if the strut bearing is not aligned with the stern tube to the extent that the shaft can't be made to align properly with both and the strut needs to be cast loose and reattached.

There are plastic bearing materials that are longer lasting and have less friction than the standard Cutlass. Thordon is the most common name. They are available in standard Cutlass sizes but also in blanks that can be machined. Large vessels often have their bearings installed by pumping a special epoxy resin called "Chock Fast" around the bearings and also use it under the engine mounting feet.

You might be able buy a blank of Thordon, have it machined to size with sufficient clearance in the strut to secure it with Chock Fast. You put the bearing on the shaft, line everything up, and pour in the resin after damming up the ends with clay or putty formed into a pouring lip.

The result is perfect bearing alignment and a bearing you can remove with a torch instead of going through all the grief often discussed here. You probably never will have to replace a Thordon bearing on a sailboat though. It's what they use for the cutter head shafts of dredges. You can also get it in self lubricating versions that won't be ruined if you accidently leave the engine in gear while winterizing out of the water.

The only caveat with Thordon is possible problems if you take the boat from very cold to very warm waters. Some high power boats have had issues due to thermal expansion but a bit of extra machining allowance should take care of that for a low power engine if you plan to go to the tropics.

For a low power sailboat installation, you probably could also get by with a less expensive epoxy than Chock Fast if the minimum quantity available is too expensive.

 

[Witzend]

Roger, What is the Thordan bearing made of? Is it a solid structure using one material? Is the inside of the bearing fluted? I can see that this approach would work when you have a greater difference between the OD and the ID of the bearing. In the C310 design the total gap for the bearing tube casting wall and the Natril rubber is only 1/8" so there is very little to work with. This is why I had such issue with the Duramax bearing. Who ever decided to use a strut for a 1.25" bearing and then use a 1" shaft was an idiot!! My options are very limited here.

Paul, attached is a ROM of the alignment issues. As you can see I'm getting squeezed here. I will take some pics the next time I'm up.

This thing went out the door with a squeezed bearing, than the engine ran miss-aligned until it wore away the Natril on the top aft and bottom forward. It may be cheaper in the long run to do the same and after 500 hours change it again. In fact if I keep the alignment as high as I can, it may last longer. I also may be able to get the alignment closer by beveling the top of the inside of the tube.

Am I talking myself out of doing the right thing here, or is history telling me I can get away with it for another 500+ hours?

 

[Ed Schenck]

I for one am not understanding all the discourse. Why are you not simply aligning the strut and using a normal bearing? My first change out was after more than fifteen years and there was still not much wobble. The boat is thirty-one years old and on its third bearing. And it is the same size as you have been discussing.

I agree that a misaligned strut is something to be pissed about. But once aligned you can go ten years without thinking about it.

 

[Witzend]

Ed, the strut is glassed in deep, maybe 4-6" of fiberglass would need to be carefully removed just to get to the bolts. An almost impossible job. Can you imagine grinding or chiseling fiberglass around bolt heads!! What a mess!!! Might better just cut the strut off half way and bolt it back together again with side plates.

 

[Roger Long]

Roger, What is the Thordan bearing made of?

They are a plastic material, often made without grooves since they don't need as much water cooling. They are available in shells but often installed without.

http://www.thordonbearings.com/

I don't quite understand what you are describing with your bearing but, if it does not take a standard Cutlass bearing there may not be room for the fix that I suggest which would require having a bearing made the thickness of the rubber portion and using Chock Fast in the space previously taken up by the bronze shell.

With careful measurement and a good machinist, you might be able to have a Thordon bearing made up with an off axis bore that would fit the strut. You would have to be sure to get the right part at the top and keep it from rotating with set screws. If you go this route, it might make sense to have two bearings made while everything is set up for the machining. It's the set up that takes the time. You'll probably never replace a Thordon bearing though.

 

[Witzend]

It does take a standard bearing, it just the thickness of the tube wall combined with the Natril rubber is only 1/8" so there is not much to play with. Looking at the Bearings from Thordon they appear to manufacture ones without any flutes, I could get a blank from them and drill it myself correcting for the miss-alignment. It may be expensive to have them do it. I will contact them.

 

[Ed Schenck]

Witz, you promised pictures long ago. If the strut is "buried" as you say then are you still convinced the factory did that? But to answer your question, yes I would definitely "unbury" it and make it right.

My strut mounts solidly on the keel(picture).

 

[BobM]

Check your engine mounts and bed

I have a similar problem on my boat, but it is likely due to aging engine mounts and the fact that S2 laid the wooden stringers the beds are mounted to on huge gobs of now decaying epoxy putty. They did this as it was easier than making the compound cuts necessary to fit the wood to the hull properly.

That being said, I also advise that you not get too excited about an "alignment" issue for a boat on the hard. I changed my whole drive train from the coupler back only to ultimately conclude that it is difficult to judge alignment with the boat out of the water. I could just be sitting on the stands funny.

 

[Witzend]

Witz, you promised pictures long ago. If the strut is "buried" as you say then are you still convinced the factory did that?

Ed,

I just discovered the strut alignment issue yesterday and did not have my camera with me. I have had many problems I have discussed with this board and have provided many pictures within. Such as my Damper problem.
http://forums.catalina.sailboatowners.com/showthread.php?t=113844

Your strut is surface mounted, the C310 is not and is desiged that way from the factory, please refer to what Maine had to say about it in the previous post.

Yours is not the only C-310 to suffer this problem. A guy in my town owns what I believe is a 2001 or 2002 310 named, I think, Annie O'day.

His strut was re-aligned by Handy Boat in Falmouth, ME under warranty. I should have snapped some photos because the strut bolts are really, deep up in the hull and it is filled with lots of thickened glass. It took the yard quite a while to fix this.

 

[Roger Long]

It may be expensive to have them do it. I will contact them.

Check around your area for small non-marine machine shops. I've always found the people who run these to be remarkably helpful and had things done at surprisingly low prices. Many of them are semi hobby operation, at least in my part of the world, and they like doing something unique on a boat.

The expensive part will be the measurement if you don't do it yourself. Get a good set of measuring tools. To do it right, you'll probably need to pull the shaft and run a tight wire through. If the bearing is worn enough, you might be able to do it by getting the engine aligned so the shaft is in the center of the shaft log and then measuring from the shaft to the wall of the strut barrel.

 

[Witzend]

Bob, I considered that sitting on the hard could be contributing to this, but it is quit extreme and would be surprised if the hull was flexing that much. I have new OEM motor mounts now which will be mounted on 3/4" blocks so the adjustments will be near the bottom of the posts. After final alignment in the water I should be more stable.

 

[Witzend]

Roger, I do know some shops in the area to check with.
I agree, measuring the offset will be critical. I like your idea of running a line for reference.

 

[Stu Jackson]

Just occurred to me that if you're going the route of exposing the bolts for the strut this may be an opportunity to simply get a new strut that will accommodate a "proper" cutlass bearing of the correct dimensions to avoid this issue in the future. Good luck.