Stern tube lubricating system.

Philip_Oceanis 361 · Apr 17, 2015

Onelife said:
Hi All
Beneteau 411 Celebration 2003
I have a problem with the stern tube lubricating hose. It has snapped off. All sealed up for the minute but cannot find a detailed drawing of what needs to be replaced. Has anyone had a similar experience? Do i need to take the yacht out of the water or can it be done without lifting her. I am taking it that if I easy out the remainder of the stub I will simply have to screw a new one in. If this is the case would you recommend using some sort of locking adhesive when refitting. Thanks

This is a common problem unfortunately http://forums.beneteau.sailboatowners.com/showthread.php?t=84668
Mine broke of too, but the boat was out of the water and I actually pushed the hose by accident.
If you are fast and brave and can seal up quickly if doesn't work out then remove (unscrew) the remaining of the fitting and screw a new one. Otherwise you will have to take the yacht out of the water.

Philip_Oceanis 361 · Apr 17, 2015

Onelife said:
Hi thanks for the reply, can you tell what size thread is on the fitting and did you use any type of locking liquid when fitting? I think the threaded fitting screw directly into the grp stern tube? Is this correctc? Thanks again for you reply much appreciated

Unfortunately I don't remember the size but even if I did it's probably not the same. My boat has a 25mm shaft and yours, I guess, it's 30mm. So if the shaft tube on yours is also bigger then maybe a different size fitting is there (this is all guessing of course).
I remember using loctite. If you see my photo attached the fitting is screwed directly on the grp shaft tube. Not actually on grp but there's a little piece of metal there.

Gunni · Apr 17, 2015

This is a Beneteau part, contact your local Beneteau dealer (or possibly France) for the correct fitting. Your other option is to replace your seal with an aftermarket. Something like the PSS system from PYI, Inc. What you have is a Volvo part.

BigEasy · Apr 17, 2015

I checked with Ward at Beneteau USA. He told me that the replacement fitting & epoxy kits that Beneteau used to stock are no longer available (part number 460646). He advised buying a fitting locally.
Unfortunately the brass fittings that I have been able to find do not have an adequate wall thickness as compared to the OEM fitting. I removed the fitting on my my 7 year old Beneteau last year. The original fitting seemed to be quite strong with no evidence of corrosion. The epoxy bead that was placed around the fitting at the factory was sound; therefore, I placed some Teflon tape on the threads and reinstalled it with a bit of 3M4200 on the Teflon coated threads--no problems to date.
Just recently, someone on a Ben 343 site, reportedly had the same problem with the fitting snapping off. He was able to locate a fitting and epoxy kit from Annapolis Yacht Sales.
I spoke to the parts manager at Annapolis and she told me that they started to sell their own kit, that includes the brass fitting & epoxy, since Beneteau USA no longer sells it. The cost from Annapolis is $25. I just received the kit since I wanted to have a spare fitting just in case I have a problem with my installed fitting. The fitting that I received from Annapolis doesn't appear to be the same size as the OEM fitting that I removed and inspected. The OEM fitting is 1/8"NPT x 1/4" or possibly 3/8" straight barbed; the fitting from Annapolis appears larger. Guess I will find out when I haul out again next year.
There is an abundance of information about this problem on the Yahoo Beneteau423 site. Several of their members have reinforced/thickened the shaft tube, where the fitting is located, with layups of fiberglass. The layups were then retapped to the appropriate thread size and a new fitting installed. This provides a much stronger installation as all of the fitting threads are engaged in the layup. Some members eliminated the entire problem by converting to a PSS shaft seal, as Gunni stated. You can view the photos on the 423 site.
As far as attempting this repair in the water, it may be a bit risky. A "quick haul" might be the safer alternative. With the boat suspended in the slings, out of the water, you can try to replace the fitting---if you have problems, you can have the boat hauled & blocked.
I would try to use the appropriate sized "Easy Out" drill to attempt to engage the broken fitting that remains in the shaft tube and then unscrew the fitting using the "easy out". If you are successful, you won't have to drill out the broken fitting and then have to retap the shaft tube to a larger size.
Please let us know the outcome as we are all going to have to deal with this poorly designed assembly in the future.

BigEasy · Apr 17, 2015

Giving this thread further thought; It would be a terrific service if the Beneteau owner's store on this site would offer the EXACT OEM shaft tube fitting for sale in the store. On the Yahoo 423 site, one poster stated that the fitting has a 10mm wall thickness and non tapered 1.5mm threads. The fittings that I have found at local hardware, lowes, & home depot are so thin that I opted to reinstall the original OEM fitting because it was more robust than the new fittings that I purchased. There has to be a manufacturer out there that supplies these fittings. Beneteau USA would not give me the name of the original manufacturer. I know that I would be willing to pay a premium price for a quality fitting as would others. It is ridiculous that a low cost brass fitting can sink your boat. I would ask the "store" to provide this part service to Beneteau owners. All of us would sincerely appreciate the help.

BigEasy · Apr 18, 2015

Yep, that is exactly what my fitting looks like (sans broken threads) on an '06 Ben 343.
Can't find anything that is even closely resembles the OEM fitting. Somebody out there makes these fittings and they should be available. I wouldn't have a problem replacing it every two years on haulout just to ensure that it isn't corroding, with the potential for snapping off as yours did. Very easy to unscrew it, place some sealer the new fitting, and reinstall---if the fittings were available.
Here is a link to the photos of the "beefed up" stern tube following additional fiberglass layups on a Ben 423 stern tube. Shows a new SS fitting that has all threads engaged in the thicker stern tube. Nice work. http://groups.yahoo.com/group/Benet...de=tn&order=ordinal&start=21&count=20&dir=asc
The stern tube modification is on the last row of pictures.

Philip_Oceanis 361 · Apr 19, 2015

May I ask why this fitting exist in the first place? Is it to lubricate the volvo seal? And why not all Beneteau (or similar installations in other boats) have it?

Captn TJ · Apr 20, 2015

To lubricate/cool the cutlass bearing. In other boats the cutlass resides in a separate skeg and is exposed to water on both sides.

BigEasy · Apr 20, 2015

I Read the following on the Beneteau 423 site. Not sure that this is factual; however, it is interesting.
"The need for inducing water flow is critical & vital to the life of the cutlass bearing. Some of the newer Catalinas utilized an integral skeg like the Beneteaus. Initially, Catalina did not appreciate the need for circulating water in the shaft log and all of the early boats experienced premature cutlass bearing failures. Catalina fixed the problem by changing over to PSS seals with water circulation nipples & they tapped the engine raw water circuit as a water supply-----problem solved. Prior to about 2005, PSS made 2 seal types; one called low speed for sailboats that had no water circulation feature and one for power boats that did have water circulation. PSS then eliminated the low speed version and now all of the seals are made with the water circulation feature. In the case of Beneteaus, both the shaft seal & cutlass bearing need to be in contact with a supply of cool water, but the cutlass bearing must have water forced through it and the clearances are small. Induced water flow is indeed necessary."
The 423 contributor's opinion relates to Captn TJ's observation that boats with external skegs, that are attached to the bottom of the hull, are exposed to cooling water on both sides of the cutlass bearing.

Davidasailor26 · Apr 20, 2015

So how does this work when under sail? The tube for ours comes off of the heat exchanger, but presumably there's no water flow there when the engine's off, even though our fixed prop spins quite quickly sailing above 5kts.

Gunni · Apr 20, 2015

Get this fixed before sailing or motoring the boat any significant distance. Your transmission is not designed to handle the load created when it locks the shaft rotation under sail.

Davidasailor26 · Apr 20, 2015

Onelife said:
Hi Davidasailor. The system I have does not come from the engine feed it is a stand alone system. I presume that although the shaft may spin when under sail it will not be at the same Revs as under power. I have heard others say that when under sail, it is possible to stop the shaft rotation by simply put the engine in gear. If this is good practice or not I do not know?

I've traced our line and it definitely comes from a nipple on the heat exchanger, not a separate through hull. The owners manual shows a separate inlet, but somewhere along the production run Beneteau must've changed the design, as this is how it came to us from the factory. They also strongly recommend against leaving the engine in gear when sailing as the transmission is not built to hold the torque, so that's not an option. I guess as you say Beneteau just relies on the revs freewheeling under sail not being as high as when the engine is pushing.

Stern tube lubricating system.

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