34 Mainship III Cutlass Bearing Size?

I'm getting ready to pull my boat and do a bottom job. While out I'm going to go ahead and change the cutlass bearing. It has a 1-3/8" diameter shaft. I'm needing to know what the name of the bearing is for these boats. I already know the 3 possibilities of 1-3/8" versions. I need to know what the I.D of the shaft log that bolts through the rear of the keel on these early '80s (1983) 34' Mainships is. Or the name of the bearing used on your boat if you have ne of these vessels. Not being a jerk, but "I think I used..".. or "IIRC....", doesn't really help me. I need concrete, certain knowledge so I can go ahead and buy one of these ahead of time.

Thanks guys

Sorry, had an '87 III but cutlass bearing issues never came up.

There's a Mainship owners group somewhere, Yahoo I think.

The new Mainship owners (Marlowe) may have records on older models from previous ownership.

Buck Algonquin always made most of the cast bronze stuff for the various Luhrs-related brands, they might have info.

-Chris

Marlow will not be able to help. The records of those years of boats were destroyed long ago by Mainship when they moved to Florida.
I suggest you join the Mainship owners group in Yahoo and ask there. Just make sure you specify it is an old 34
There is also a "vintage" Mainship owbers group in Yahoo, where you might get a quicker answer.

jleonard said:

Marlow will not be able to help. The records of those years of boats were destroyed long ago by Mainship when they moved to Florida.
I suggest you join the Mainship owners group in Yahoo and ask there. Just make sure you specify it is an old 34
There is also a "vintage" Mainship owbers group in Yahoo, where you might get a quicker answer.

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I'm on the Yahoo sites as well, I just hate the format those forums still use. Also I've found this site much more active. Perhaps my boat (once one of the most popular boats) has become too old to be worthy of keeping up with online.

I also posted in the boatdiesel site but forgot to post here that you should also be thinking about changing the "mid bearing" that is attached to the bulkhead below the slider (on the aft wall). These are hidden from view, hard to access, in a horrible envoronment, and rarely get greased.
It is a Fafnir RCJC 1 3/8 or the equivilent from another manufacturer. You can also add a remote grease fitting or an automatic grease cup while you are at it. If you need details on how to do all of that ask away, I've done that job more than once. (but only once on my boat).

I don't care for that "free for all" style of forum either, but I was one of the initial members and moderators back in 99 when it started. I also owned a model I for 14 years and rebuilt just about everything on the boat including a repower so I had a lot to share with the old boat owners. So I stay involved.

jleonard said:

you should also be thinking about changing the "mid bearing" that is attached to the bulkhead below the slider (on the aft wall). These are hidden from view, hard to access, in a horrible envoronment, and rarely get greased.

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It was changed 3 yrs ago at the last haul-out. Its still fine.

twiisted71 said:

It was changed 3 yrs ago at the last haul-out. Its still fine.

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Good. Hopefully you have given it a shot of grease from time to time.
One a year, or once every other year is plenty.

Im not sure what your asking but I change my bearing on my 34II for a month ago and the size was 1 3/8 inner or shaft size and 1 7/8 outside dia.

Exactly what I'm after Mike. Now what year is your boat and what HP engine if you don't mind?

My boat is a 79 with perkins 160. Maybe you can veryfi the size by checking the dia.of the sterntube were the shaft seal is attached, my size is 2 1/4".

They will be the same. Mainship built the original 1977 and 1978 boats with a 1 1/2 inch shaft (and a straight skeg) , and changed to 1 3/8 inch shaft and a curved skeg.
The shaft change was economical and the skeg change was because they changed the shaft angle (increased) to give adequate prop to hull clearance (thus allowing a large prop dia).
It's funny though, that they didn't actually change to a larger prop until they ran out of stock of 20 inch props in late 83 or 84.

Yepp thats correct my boat has a curved skeg and what I believe is an original prop 20X20 will be modified to 20X22 this year! Another thing I wonder about is the intermediat bearing on the propeller shaft, this was completly gone but I didn't reflect over any vibrations so I was thinking of leaving this out! Any comments to that?

Mike1973 said:

Yepp thats correct my boat has a curved skeg and what I believe is an original prop 20X20 will be modified to 20X22 this year! Another thing I wonder about is the intermediat bearing on the propeller shaft, this was completly gone but I didn't reflect over any vibrations so I was thinking of leaving this out! Any comments to that?

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I once assembled my running gear without the bearing while I was on the hard. The shaft had so much whip I put the bearing back in. And that was with a 1 1/2 inch dia shaft out of Aquamet 22 one of the stiffest shaft materials out there for our boats.
The bearing makes a huge difference in stability of that shaft. No way would I ever recommend running without it. If you look at specs, these shafts are spaced longer than shaft material engineers recommend. So the bearing is necessary by design.

For a $80 bearing that will last a lifetime if it's greased, why would you not put it back?

Not for any othere reason then in fact I didnt notice it was completly wasted before I was about to pull the shaft so it looks to me that its not really needed and for the second part its a pain in the A... to get in place! But maybe I give it a try!

Along these same lines do any of you happen to have some good pics of the skeg? Just trying to take everything with me to the yard I can think I might need. I don't know if my rudder has a hole for the shaft to pass through so I guess I'll likely be removing the skeg to pull the rudder. How is it attached to the keel and the rudder's bottom post attached to it?

Hi again!
I dont have a pic of my skeg but its attached to the keel with 2 bolts that yuo can spot from the inside just below your shaft seal! My rudder do have a hole but if its original I cant say! When the 2 bolts for the skeg is loosened up it will come down by it self from the rudder!

Thanks Mike, Just what I needed to know. i haven't really gotten down and looked under the shaft. My Shamrocks all had lag bolts holding the shoe to the keel but they had solid keels.

I try a pic of my skeg!

Thanks again. I hope mine's got that same pass through on the rudder!

Every Mainship I ever saw (scores of them) had a hole in the rudder.
I once removed my skeg to replace the bolts and backing plates. While the skeg was out I spotfaced the skeg holes so the bolts had a flat spot to seat on. I also added one more bolt.
What a difference those changes made for stiffness.

twiisted71 said:

Along these same lines do any of you happen to have some good pics of the skeg? Just trying to take everything with me to the yard I can think I might need. I don't know if my rudder has a hole for the shaft to pass through so I guess I'll likely be removing the skeg to pull the rudder. How is it attached to the keel and the rudder's bottom post attached to it?

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I have a couple halfway decent pics -- although not close-up -- of our '87 skeg/rudder... but I have no way to post those here.

If it'll help and if you'd like to PM me an e-mail address, I can forward that way.

-Chris

'Preciate it guys. She's already hauled. It does have the shaft pass thru on the rudder.

twiisted71 said:

'Preciate it guys. She's already hauled. It does have the shaft pass thru on the rudder.

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You know that you have to disconnect the rudder arm inside so the rudder can be turned to 90 degrees in order to get the shaft out.

LOL, yeah got that. Not my first rodeo, by a long shot. I've been on boats and in shipyards literally since before I could walk. I just had a few specific questions regarding this specific boat. I just decided to leave the shaft alone and pull the stern tube. Much easier to do it this way and easier to bring it home and press the cutlass in and out. I can clean the tube nicely as well this way and put a nice clean layer of 4200 on things since I'm pretty sure the lower bolt on the stern tube was where I was getting water in my bilge. Stepping up from 1/2" to 3/4" tru-hull and strainer for the gen-set, 1/2" just seems absurd! Plus if I need to swap it out, it'll already be able to flow more if I get a bigger unit. Prop has been re-done. Prop scan mumbo jumbo, computer gizmo, whatever. They had a prop coated with propspeed in the lobby. Didn't care for it. It felt kind of rubbery and would roll off like silicone if rubbed hard with a thumb or finger-not to mention what a fingernail would do, :-O. I'll just be putting on several coats of ablative bottom paint like always. Wish I had some of that "hard" bottom paint to try out on the running gear. Maybe next time.

Well ended up having to replace the shaft thru-hull! What a PITA!! electrolysis had made the other one completely "dead". Trying to knock out the cutlass caused a "dunk-dunk" instead of a "ding-ding" and needless to say the tube actually broke right off the flange! It was completely "red" all the way through! So I ordered a Buck Algonquin tube (2-3/8" OD 2" ID) and had a custom inside the hull tube made to attach the stuffing box hose to. Bronze shouldn't be spelled with a Z it should be spelled with a dozen $$$$s! Anyway I'm glad it happened on the yard. I shudder to think what could have happened had I caught a crab trap in the prop!!!
Any way here's a pic of her just before splash down.

I had to replace that shaft gizmo on my old Mainship also.
However I recall it being an easy job....of course I was about 18 years younger then!! I bet that had someting to do with it.
Glad you found it now.

Changing it was no biggie. getting one-a whole 'nother $$tory.