Cutless Bearing Replacement

[Captn_Dwt]

Hi Folks,
Well, I've dug in and found lots of problems.
1) The rubber hose that the stuffing box mounts into was rotten. Caught that just in time, as it started leaking in October.
2) The prop shaft has pit corrosion in several places. It's junk. Oh, the $$$ on that one!
(interesting that the pit corrosion was equally spaced along the length of the shaft...about every 16-20 inches)
3) The cutlass bearings are shot, especially the inboard one, which brings up my question:

Has anyone removed the carriers for the Cutlass bearings? I've removed the 4 lag bolts (stainless, and badly corroded) from the inboard carrier, and the nuts from the outboard carrier, but they seem "glued" on?
How do I get these to release, please? My yard staff don't seem to have a firm answer, and I'm a strong believer in using understanding before force!

[jleonard]

Go down a few topics and there is a long thread about this.
It's a big job.

[Captn_Dwt]

Go down a few topics and there is a long thread about this.
It's a big job.

Yes, I've read that thread. There's reference to "I think the carriers are threaded to the shaft tube". I was hoping someone had actually taken these carriers off and could illuminate that particular task. I certainly can see why many have just turned away from doing this job!
Also, fortunately, there's no evidence of leaking from that tube that runs the length of the keel.

[mike66]

viewtopic.php?f=20&t=5054 Hopefully this helps, or you could PM. Good luck!

[Captn_Dwt]

Ok...like others, I answered my own question with some careful " applied brute force"....
The outside / stern cutlass bearing carrier IS indeed threaded onto the shaft log tube.
To remove the carrier, lock two nuts together on the two studs at the top and bottom of the carrier and back the studs out. (Mine will be replaced with new studs, and there was some corrosion on them)
Now, use a chisel to break away all built up bottom paint and fairing compounds or gelcoat that might keep the carrier from turning.
Threads are normal, so CCW will remove the carrier.
I used a 3# drilling sledge and a 24" pipe wrench; load the pipe wrench with all your weight, and them pound on the upper ear (top end) of the carrier. It will move if it's not seized. My threads were clean, and easy to turn, almost as if they had grease on them. I assure you, this had not been off since Day One (1980). The cutlass was disintegrating, and the keel had gel-coat blocking the rotation of the carrier.
[remind me again of why we pay surveyors? Certainly it's not to find these obvious faults]
As for the interior carrier: I deemed it not worth removing. (1) it was liberally glassed over and around the large square flange, meaning that I would have to cut all that glass away for the flange to be able to rotate, and (2) The short cutlass that's in there (maybe 3" long?) did not show a great deal of wear, and not deteriorated like the one aft.
Hope this is helpful to someone, some day!

[jleonard]

I am glad that it came out that "easily" and I thank you for the great description.
This is an inevitable job for many of us.

[mike66]

Thank you. Is it difficult to find a replacemet bearing?

[meridian]

I replaced my shaft last spring to the tune of $700 just for the shaft. 9' x 1.5"

[psneeld]

Great info!!!!!

..... additional info for others...you don't "have to" remove the carriers to replace the cutlass bearings...
They can be pressed out or cut out and new ones pressed back in with just the shaft removed.

also, if your shaft isn't too badly pitted, a good machine shop that does a lot of marine work can suggest techniques (mine suggested "flame sprayed" I think) to build up pitted areas....added a little over $100 to the work I had them do when I went to a split coupling for my shaft (had to cut the old one piece off to get the shaft out).

[Captn_Dwt]

Thank you. Is it difficult to find a replacemet bearing?

Bearing is very standard, 2 3/8 OD, 1 1/2 ID, 6" long. Prices are $75 to $105 depending on who you purchase from.
One source is http://www.deepblueyachtsupply.com/mari ... umber/BRAD
"BRAD" is the code for this bearing in a brass sleeve.
Many thanks to those who have expressed some appreciation for my post. It does feel good to know I've contributed!

[Captn_Dwt]

Great info!!!!!

..... additional info for others...you don't "have to" remove the carriers to replace the cutlass bearings...
They can be pressed out or cut out and new ones pressed back in with just the shaft removed.

also, if your shaft isn't too badly pitted, a good machine shop that does a lot of marine work can suggest techniques (mine suggested "flame sprayed" I think) to build up pitted areas....added a little over $100 to the work I had them do when I went to a split coupling for my shaft (had to cut the old one piece off to get the shaft out).

In my 6 years working with a construction company with LOTS of old heavy machines, we did some pretty outrageous repairs to units for which no parts were available. My experience would not encourage me to repair a pitted shaft.
In this application, the shaft is very long an mostly unsupported. The load is TORQUE, and the shaft will flex (as some have called it "whip"). Surface deterioration will weaken the shaft, causing fracture points that will leak to breakage. Repair techniques all would require welding heat...and that could result in increased brittleness or uneven hardness, which further increases the chance of breakage.
Given the critical nature of the shaft's function, the amount of damage to the boat and danger to its occupants in the event it breaks, I would opt for a new shaft every time.

[jleonard]

However, flame spraying (and other similar techniques) is a very common repair for a prop shaft, esp one that carries very low torque like our trawlers. I should do a safety factor calculation, I'll bet it's huge.

Normally though the corrosion is only where one cutlass bearing is, not over the entire length of the shaft.

[psneeld]

Put well over 2000 miles on that "repaired" shaft last winter....

Even if I get a few years out of it before it snaps or I catch it again before it snaps and get it repaired yet again....I'm way ahead of the game...

If I was going offshore or where there wasn't towing assistance...I "might" be concerned ....but when the top prop/shaft machine shop in a big boating and boatbuilding area recommends and does it...I'm not too concerned.

[Parrot Adventure]

20160120_115957_HDR.jpg

I recently replaced our external cutless bearing on our 1981 Albin 36 aft cabin. The boat was hauled out at a local marina, and I decided to do the cutless bearing replacement after reading about the topic elsewhere in this forum. NOTE: I understand from this forum there are TWO cutless bearings in the Albin 36 aft cabin: one aft of the stuffing box where the propeller shaft exits the hull INSIDE the boat under the aft cabin sole, and another cutless bearing at the aft end of the keel on the bottom of the boat. My discussion only details removing the external cutless bearing housing and the bearing itself. From what I can tell, our boat's cutless bearing was last replaced by the first owners during 2000 while the boat was in Baltimore. If so, this cutlass bearing lasted 16 years as it is 2016 as I write this. While the job itself was challenging, the biggest and most important piece of the puzzle is recognizing the exterior bronze cutless bearing housing located at the aft end of the keel is THREADED onto the shaft tube. However, on our Albin 36 there were also two 1/2" stainless steel studs holding the housing onto the keel. The studs are threaded into nuts which are embedded in the keel when the boat was built in Taiwan in 1980. You first need to carefully remove the two stainless steel studs before you back off the bronze cutless bearing housing. Alternatively, instead of removing the cutless bearing housing, I could have pulled the shaft, but being a passionate DIYer I wanted to do the job myself so I could learn the process and share my experience with this group. Even if you never intend to change the cutless bearing yourself, I hope someone reads this and relays this information to the boatyard who may not be aware the exterior/external cutless bearing housing is threaded onto the shaft tube where the housing is attached to the keel. I will attempt to post photos of the process. I will also attempt to post detailed explanation of removal of the bearing from the bronze housing, as well as installation of the new cutless bearing into the housing as well as re-installation of the housing and new bearing back onto the boat. My name is Mark and we live in the Tampa Bay area of Florida. Our boat is a 1981 Albin aft cabin 36 foot single diesel engine trawler named PARROT ADVENTURE. We are the third owners of the boat and have owned it since January 2012.

[Captn_Dwt]

I found those "studs" you show...the ones badly corroded..to be an odd thread. You may have to have a set made-up at a local machine shop.

One more note: In my post about how I did this job and replaced my Shaft....I did not explain that the corrosion was at 3 or 4 locations, looking as if the shaft had been "welded up" from many smaller parts instead of one very, very long rod. This contributed to my decision to replace and not try and repair the shaft.

Good photos, Mark!