Cutless bearing, flex coupling and PSS packing gland

[thaisail]

I have just received two Johnson Duramax cutless bearings that were shipped from Florida to Phuket, Thailand and discovered that the aluminum sterntube is too large and the new cutless bearings do not fit without a lot of play. The old plastic bearing was 52 mm in diameter and the new Duramax is 51 mm or 2 inches in diameter. It may be that this boat always had a 52 mm ID on the aluminum stern tube. The shop I ordered them from in Phuket, agreed to give me my money back which is very kind of him. He recommends a special material that must be ordered from Australia which is some sort of special plastic that can be machined into a cutless bearing and he claims that these type of composite bearings will last twice as long as the Duramax. He claims to have put one of these on a boat that has already done heavy commercial work for 10 years and still does not need replacement. I am a bit skeptical about this and would like some other opinions about this. The same shop also advised against the Centaflex coupling that I had to destroy in order to get the shaft out of the boat. I am now having the keyway on the inside end of the shaft welded up and the shaft turned on a lathe so that the new Centaflex will have a smooth surface to grab on to and hopefully the insert will not "glue" to the shaft like the last one did requiring an angle grinder to remove the tapered male insert that seemed to have welded itself to the shaft. The other likely cause of this disaster was that seawater from the packing gland got up inside the tapered insert and rusted the mild steel onto the shaft. I have decided to replace the old style packing gland will the PSS dripless packing system so that the seawater will no longer ruin the centflex coupling. The PSS is around 6.5 inches long when it is compressed and the flex coupling is 4 inches long and there is 10.5 inches between the stern tube where the PSS rubber will bottom out and the gearbox flange. This means that once compressed there will be less then one millimeter of space between the end of the PSS and the Centaflex coupling. I hope that I will be able to compress the bellows on the new PSS enough to allow me to fit the bolts that will pull in the tapered insert to the Centaflex coupling! But my main question is about the material used to fabricate the cutless bearing being as good or better than a Duramax cutless bearing. Also, the shop tells me that the Centaflex coupling is big problem and should be avoided due to potential failure. I have had mine on the my boat for 3 years with no problem other than getting stuck on the shaft which is my fault for not sealing the insert with silicone to keep the seawater from getting between the shaft and the insert for the coupling. But I was told that the Centaflex is designed for those who cannot do a good alignment of the gearbox to the shaft and can allow for up to 3 degrees of misalignment. Anyway, please if any of you out there have had some experience with any of these three items, please let me know.

[Tia Bu]

I replaced a dripless shaft seal last year. What a miserable job! I imagine your frustration level is sky high at this point. It doesn't sound to me like you have left yourself enough room to work with the shaft seal. Maybe leaving off the Centaflex coupling is not a bad idea.

I don't know about the material for the cutlass bearing, but what the heck? It's just a cutlass bearing. Put the whole bloody thing back together the best you can with the parts that are available, align the engine the best you can, and get back on the water. That's a miserable spot to be working in on a boat, and it's best to get back out of there, IMHO!

Now, surely someone will disagree. :-)

[Cheechako]

Wow, how frustrating, ......I've often wondered why they are rubber inside rather than something like teflon or delrin......
Aluminum shim stock ....? Does it have set screws?

[NCboatrx]

The shop is quite correct about the phonelic type of cutless bearing. These have been used on commercial vessels for many years (more than 100 years!). The "yachtie" type of cutless bearing, like Johnson ones, is a relatively new product which has been around for 40 or 50 years. If the correct material is used for a cutless bearing and the machining allows for expansion in salt water, you should have a superb cutless bearing for many years.

I disagree with the shop however with regards to the Centaflex shaft couplings. We have had excellent results with them when they are properly installed.

Stanley

[NoTies]

The cutlass bearing material is fine and if properly installed will do as they state. I assume your shaft has 2 bearings and your engine has flexible mounts. If so then you MUST fit a flexible coupling. If the yard is telling you otherwise then it would be wise to back up any statement they make with knowledgeable advice.

[barnakiel]

We have a Johnson Duramax here. No issues. Our old bearing was at least 10 y.o. when we replaced.

I too subscribe to the opinion that engine alignement is more essential when two bearings are present (longer, finer shaft). However none of the manufacturers of various devices recommends theirs as a cure for misalignement. They do allow for some gearbox shaft/propshaft angle though (I think).

b.

[thaisail]

Thanks to all of you for your very helpful advice. The saga continues and I may need more advice. I checked my shaft on a lathe machine and found out that it was bent slightly. I am now trying to find some new material to make a new shaft. So far in Phuket, I have found both 304 stainless and 316L. L is for low carbon. I have no idea what material Kanter Boat Yard in Onterio, Canada used for the original "now bent" shaft in 1982 but it has served me well so I will not complain. The cost for the material her in Phuket, 1-1/4 inch diameter at the required length is around $50 in both materials. The machine shop quoted me another $30 to do the keyway, taper and threads as well as making me new propeller nut. I would like to hear some feed back from others about what material their prop shafts are made from.

Now for the cutless bearings, the shop that sold them to me has taken them back and refunded me all the money including the shipping. I found the following link on line: http://morserubber.com/pdfs/Marine%2...ptlstnmMRL.pdf

It seems that there is a special cutless bearing that will fit my odd sized stern tube once the new bearing are machined to fit. The EF1200 Capelin is 2-1/8 inch which should be perfect for my stern tube that is 52 millimeter ID. Now I just have to find a supplier and order another two bearings, one to fit and the other for spare.

I managed to find the PSS PYI dripless packing gland at Port Supply for $250 and I am still working to find a good price for a new centaflex coupling to replace the other one that I had to cut off with a grinder. Right now I am trying to get one from the US division of Centaflex but it will have to be shipped from Germany to Centa US first. So far, my best price is from Beta Marine for 150 pounds sterling. But shipping from the UK is ridiculous! Anyone out there who know where I can get a Centaflex coupling from in the US for a good price?

To answer the question posed by others, I have only one cutless bearing and the new 27 HP Beta engine is mounted on rubber engine mounts. I think with a new shaft, new cutless bearing from Morse, if they still exist and the PSS PYI dripless packing gland, I should be good to go! What else can break!!! With the new Michigan Wheel I will have a completely new drive train with the new Beta engine and gear box! I just have to make sure that it is lined up perfect this time. Any recommendations on how to align the gearbox with the shaft without using the new Centaflex coupling? I was told that it is useless to do the alignment with the flex coupling in place. This means that I will have to fabricate a steel flange with the same diameter of the gearbox output flange and have hole cut in the middle of the flange with same diameter of the new shaft with as tight a fit as I can and use a feeler gauge to check the distance between that flange and the gear box flange. That is the best idea I can come up with for the moment.

[thaisail]

Originally Posted by NCboatrx

The shop is quite correct about the phonelic type of cutless bearing. These have been used on commercial vessels for many years (more than 100 years!). The "yachtie" type of cutless bearing, like Johnson ones, is a relatively new product which has been around for 40 or 50 years. If the correct material is used for a cutless bearing and the machining allows for expansion in salt water, you should have a superb cutless bearing for many years.

I disagree with the shop however with regards to the Centaflex shaft couplings. We have had excellent results with them when they are properly installed.

Stanley

I am very interested in getting more information about this Phonelic material. Do you know where I can get it? I used another type that I got in Phuket a few years ago and it was a disaster! lots of vibration each time I left the boat for more than a couple of months as soon as I put it in gear. But only for a the first few minutes. After there was no noise or vibration and if I just anchored overnight, there was no noise or vibration. So, this time I really want to get the RIGHT material. Some say I can get this is Australia but I would rather get it from the states so that I can bring it back with me in my suitcase!

[cal40john]

http://www.cruisersforum.com/forums/...ngs-36948.html

[delmarrey]

52 mm seems to be an odd size on the market. I wonder why someone would make the tube that size.

Anyway, you can take a standard 2-1/8" OD non metallic bearing and machine off the excess .078" making it 52 mm. I say non metallic because it's going into aluminum. Cutlass Bearings -Johnson Duramax Cutless Bearing -Non Metallic Standard

As for the coupling, I'd suggest going with a standard coupler and installing a R & D flex-coupling. -- PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D -- You can get both the PSS and flex at PYI, and a coupler too if you like their design.

This way you can align the shaft using the standard coupling then slide the shaft back the 1/2" to 5/8" and install the flex coupling. You didn't mention you shaft size but the distance between the cutless bearing and prop is suppose to be 1-1/2 X the shaft diameter, which does allow the shaft to slide forward for the alignment.

BTW I would be a bit worried about using Phonelic, depending on where it's made and grade. Phonelic is a fiber compressed with a resin. Different grades have different fibers and resins. And unless you get just the right stuff it could wear the shaft or wear out itself in a short time.

[DeepFrz]

Here is a good link on propeller shaft material. Inboard Hardware: Propeller Shafts

[thaisail]

Originally Posted by delmarrey

52 mm seems to be an odd size on the market. I wonder why someone would make the tube that size.

Anyway, you can take a standard 2-1/8" OD non metallic bearing and machine off the excess .078" making it 52 mm. I say non metallic because it's going into aluminum. Cutlass Bearings -Johnson Duramax Cutless Bearing -Non Metallic Standard

As for the coupling, I'd suggest going with a standard coupler and installing a R & D flex-coupling. -- PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D -- You can get both the PSS and flex at PYI, and a coupler too if you like their design.

This way you can align the shaft using the standard coupling then slide the shaft back the 1/2" to 5/8" and install the flex coupling. You didn't mention you shaft size but the distance between the cutless bearing and prop is suppose to be 1-1/2 X the shaft diameter, which does allow the shaft to slide forward for the alignment.

BTW I would be a bit worried about using Phonelic, depending on where it's made and grade. Phonelic is a fiber compressed with a resin. Different grades have different fibers and resins. And unless you get just the right stuff it could wear the shaft or wear out itself in a short time.

I made the same mistake the former owner made and ordered the wrong size Duramax with a 2 inch OD. I did not know that there was a 2 1/8 inch OD Duramax available for a 1 1/4 inch shaft. Luckily the guy that sold me the two 2 inch Duramax took them back and gave me a full refund including the shipping to Thailand from the guy that supplies the bearings to Deepblueyachtsupplies. I will not buy from Deepblue since they sent me a damaged Michigan Wheel a few years ago to Malaysia and refused to replace it with a new one even though the box they shipped it in was not damaged. They are crooks as far as I am concerned. I carried the damaged prop all the way by hand in my suit case from Phuket to Fort Lauderdale and all they did was grind off the damaged part of the blade!

However, Lauderdale propeller will sell the same duramax bearings for $6 less but only to a retail store with a tax ID. I will have to find another shop to buy them for me since it is a matter of principle now.

As for the flex coupling, the Centaflex is a much better designed coupling and allows me to use the tapered insert to connect the shaft with no keyway to the flex coupling. The alignment is only the concern as I no longer have the old coupling that was replace with the centaflex coupling. I will have my local machine shop make up the flange to the same diameter as the output flange on the new gear box and then fit it with a tight fit on the new shaft just to make the alignment and then remove it to fit the centaflex once the engine is aligned. It will be a tight fit with the PSS dripless packing gland but I think that there is is enough room if I squeeze back on the bellows just to be able to get the screws in to tighten the tapered insert into the flex coupling cone.

The only missing link now is to find the new Centaflex coupling in the US for a decent price!

[thaisail]

Originally Posted by DeepFrz

Here is a good link on propeller shaft material. Inboard Hardware: Propeller Shafts

Excellent information that confirms all the things that I have learned so far. The problem in Phuket and all over Thailand is the same as all the fake Rolex watches. How do you know if the shaft material is 316 or 304? I asked the guy at the shop that had the 316 shafting for documentation to prove that the stainless was 316 and he just laughed at me. However, another Thai friend who has another machine shop told me about an acid that I can buy locally that when applied to the stainless 304, it will turn red and when applied to high grade 316, it will turn black. Has anyone heard of this? Or any other way to identify the grade of stainless.

[DeepFrz]

Identification Tests for Stainless Steels
Leave it to google...

[NCboatrx]

Here is a link to a company that makes custom cutlass bearings for for the shipping industry Catalog: Composite Shaft Bearings: Propeller, Rudder and Other Application: