Prop Fell Off! Help!

[MidLandOne]

Originally Posted by Steve Rust

There at the dawn of history. Maybe you met a young Jim Brown as he was with Piver at that time.

I met Piver briefly (I say briefly because I was just a little kid so not really part of the conversations ) when he was doing the Pacific on "Lodestar". He had another as crew with him - I have had a trawl around the internet to see if I could find who that was but no mention. However, I don't think it would have been Jim Brown else he would have likely been mentioned as having done so.

They returned to the Atlantic via Cape Horn so maybe one of the earliest tris to do so (1962-63'ish)? I actually sailed beside them part of the way - oh well, about a 1/4 mile or so of it anyway in my little sailing dinghy before they out ran me .

Getting back to some relevance to the thread I don't recall "Lodestar" having a prop to fall off ?

[Ex-Calif]

Originally Posted by josef

Thanks Alan Wheeler but if you assert it was not a design fault and merely "lack of maintenance" why then have Yanmar now confirmed to me that they had a design change in the prop shaft of the SD 20?

I work in customer service of some very expensive product. These comments are interesting because this is a common discussion that we have.

I build a product and I warrant it for a period of time. I specify what maintenance must be done to keep the warranty valid. I limit the time for which the warranty is valid. I design the product to exceed that warranty.

After the warranty period the part fails. I feel I met my obligation and you should buy a new part. You claim that the part failed because of a design defect. However in my original warranty, I never warranted a "perfect" design.

I have had endless discussions about "design defects" - The bottom line is that you cannot warrant the design. You can only warrant that the design will meet the warranty period.

One reason is that design technology changes. We do finite element analysis and 3d modelling today that was not possible even 15 years ago. We have a 20 year product life cycle. Designs in service and shipping today could have been put on paper in 1988 or earlier.

Now "liability" protection is different. The statutes for prioduct liability vary but when a part can cause direct harm and is still within the product liability window the manufacturer will often redesign a part, issue a service letter or maybe even make a recall.

The bigest issue is that as a manufacturer it is almost always impossible to verify that the product was used and maintained within the guidelines laid out in the warranty. Most good manufacturers know this and won't deny warranty if a "record" of periodic oil and filter changes cannot be produced. However reality is most consumers don't do their part.

It gets a lot more problematic if the part or system (think saildrive or engine) has been overhauled by Bob's boat repair. Your warranty should now come from Bob, not the manufacturer.

[josef]

Very fair comment Ex Calif.I was really interested when posting originally to ascertain whether or not there had been this problem and if so when and was there a recall or warning issued.I bought the 1998 boat 3 years ago and Yanmar now tell me they changed the design about 5 years ago.Was the previous owner made aware of this and if so did he take any action to mitigate potential problems prior to selling the boat on to me? Or should my surveyor have been aware of this issue and advised me accordingly?

[Tellie]

Believe this is a design flaw or not these props fall off far too frequently to consantly be the fault of the owner. The engineers who designed this unit do deserve some egg on their face for this poor setup. A simple thing as a circlip in front of the cones shaft thread through the cone would have solved this. I've had motors from 12volt trollers to 200 hp outboards and beat them like a redheaded step child and I never lost a prop through groundings, rocks, hard reversing etc. I rely on loctite as well on my SD20s, but in my limited and less than rocket scientist experiance, you shouldn't basically have to glue your prop on.

PS Someone posted earlier that the nylon washer that goes between the prop and prop cone was $50, they were that much but I bought two yesterday for $6 a piece from Complete Yacht service in Ft. Lauderdale. So some good news from Yanmar.

[Ex-Calif]

Originally Posted by josef

Very fair comment Ex Calif.I was really interested when posting originally to ascertain whether or not there had been this problem and if so when and was there a recall or warning issued.I bought the 1998 boat 3 years ago and Yanmar now tell me they changed the design about 5 years ago.Was the previous owner made aware of this and if so did he take any action to mitigate potential problems prior to selling the boat on to me? Or should my surveyor have been aware of this issue and advised me accordingly?

That's the next issue. If a recall or warranty "deal" is published the bean counters have to put the liability on the books. The letters are sent out to the owners of record and the manufacturer maintains the program for a while.

At some point the bean counters look at the remaining liability on the books and say, "OK. We've had 75% participation in 12 months. Let's close the books on this." The letter usually has a time limit to respond.

Once again is it the owners doing their part or not?

I would say a good surveyor is one who knows your boat and if there are any notices, has awareness.

Once again however I am relying on my aviaiton experience where all craft are registered, there is a regulatory agency that maintains all critical service bulletins as an AD note and most manufacturers will have a website with all the "non-critical" service bulletins.

It's unfortunate but even the auto industry seems to do a better job of this than the boating world.

[Dreaming Yachtsman]

My apologies to the Forum for reviving this dormant thread but it applies directly to my situation. I have now joined the surprisingly large club of boat owners who have lost their port propeller from a Yanmar SD 20 saildrive.

BACKGROUND INFO:
Three days ago my port prop fell off within a few hours after getting underway for our present location, Golfito, Costa Rica. Fortunately our approach to the mooring buoy here was right on the mark with negligible current and wind. I sent a PM to Sean Sullivan with several questions about his similar loss but have not heard back from him yet. Neither have I heard from my Yanmar parts supplier in Seattle that she has found a replacement prop for me.

Our son and two of his friends will be flying to Panama City on August 12 to help us take the boat through the canal. Obviously we need both props for that transit so I am contemplating leaving here on Tuesday or Wednesday morning (govt holiday on Monday), stopping at a couple of Western Islands in Panama for a day or two each, then heading directly for Balboa to try to find a replacement.

QUESTIONS FOR THE FORUM:
1. Would I be foolish trying to round Punta Mala, Panama, at this time of year with only one engine?
2. What are the chances of finding a fixed two bladed 12x16 prop in Panama?
3. Where can I get the parts (prop, prop nut, spacer, washer, bolt) in the USA?
4. Would I be better off trying to get a replacement prop sent here to Golfito?

Any help you can give me will be greatly appreciated.
Thanks,

[imagine2frolic]

Lamb's Yact Center | Jacksonville, Florida

I recently bought my props, and all hardware for it here. They can ship anywhere too. Best wishes, and I wouldn't go with only one prop. I have 3 extras on the boat.

[ssullivan]

Sorry... quite a bit of work the last couple days.

Imagine2Frolic has set you up with a source for your parts. It's important to note that the Volvo props fit on the Yanmar SD20's as well. In fact, Yanmar doesn't even make props. They are Volvo props anyway. So... if there is a local shop for Volvo, they can get you the 12x16 you need.

The most important thing to do is use Locktite or Permatex and make sure you crank the prop nut on until you think it's about to break.

I've had no loosening issues since using Permatex and cranking them ridiculously tight. Everything is fine now, blasting in reverse or sailing at top speed.

If you do it right, they won't fall back off.

[Dreaming Yachtsman]

Capt. Sully and imagine2frolic,

Thanks for your prompt feedback. I'll call Lamb's on Monday - they were not answering phones late yesterday (Saturday) when I tried to call.

What about installing the prop waterborne?

Someone needs to solve the mystery of why props keep falling off, though. I talked with Yanmar technician Bob Buchanan in Mazatlan who reinstalled the prop last September after replacing the saildrive seals. He reassured me that he put loctite on the "locking" bolt and tightened it securely. He also is at a loss as to why the prop would come off. Could it be a conspiracy perpetrated by the prop manufacturer?

[ssullivan]

Originally Posted by Dreaming Yachtsman

Capt. Sully and imagine2frolic,

Thanks for your prompt feedback. I'll call Lamb's on Monday - they were not answering phones late yesterday (Saturday) when I tried to call.

What about installing the prop waterborne?

Someone needs to solve the mystery of why props keep falling off, though. I talked with Yanmar technician Bob Buchanan in Mazatlan who reinstalled the prop last September after replacing the saildrive seals. He reassured me that he put loctite on the "locking" bolt and tightened it securely. He also is at a loss as to why the prop would come off. Could it be a conspiracy perpetrated by the prop manufacturer?

He he... I'm often one for blaming the company, but in this case, I don't think that's the case.

I would caution against installing the prop waterborne because the Permatex (at least the stuff I used), while waterproof, needed to be applied in air to dry properly. It could not be applied underwater, though it says it will hold up underwater once dry.

The guy who put on your bolt should have also applied the Locktite to the cone as well. In my experience, the cone tends to loosen as does the locking bolt. The cone is what holds the prop on, the locking bold holds the cone (sort of, but can still allow the cone to rotate). Locktite the whole mess - except the splines the prop slides onto in order to be certain there will be no further movement of cone or bolt.

Also, the torque values are:

50 fl-lb (7kg-m) for the Cone Nut

and

11 ft-lb (1.5kg-m) for the Locking Bolt

Be sure to tighten them AT LEAST to this Yanmar spec. Overtightening does run the risk of damaging the shaft or cone, but I ran that risk on my boat to be sure. I went just a hare over each of these suggestions and used semi-permanent Permatex. DO NOT use the Permatex/Locktite you have to heat to 350 degrees to release. Use the stuff you can release with hand tools. You never know when you might have to get the prop off, and you may not have a heater like that handy.

Best of luck... and if you have any more questions... please feel free to ask.

[imagine2frolic]

If it is absolutely necessary to do it in the water. I flattened the bolt that goes through the cone on two sides. Not directly across from eachother. After tightening everything down. I broke off the shaft of a small screwdriver, and forced it into the hole in the cone with a small hammer. It held for 1000 miles until I hauled the boat, and redid everything with blue loctite. It has held another 2000 miles with just the loctite applied out of water.

[capt bligh]

Ooh the lost prop nightmare. I operate several day charter catamarans. Last October we were bringing a 55 footer down from NY, when we lost our starboard prop in a storm off of Hatteras. Of course we didn't see this until we were back in port. As this catamaran is rigged for fair weather, we thought we were being responsible by motoring instead of sailing. Battling 58kt winds with one 30hp nearly ended in disaster. Luckily we had a spare prop with us and were able to instal it while waiting out the gale. 100 hours later after a charter in Miami, (and while docking the catamaran) I noticed the port prop was gone. We hauled out and installed 2 new props under the supervision of a diesel mechanic of 30 years. With the strongest lock-tite (the gel type) as much torque as we dared, and still lost a prop after about 100 hours. This is on a Volvo saildrive, D130. With the cone and allen screw. Now that I see that we aren't the only ones with this problem, I think this seems to be a design defect. Any ideas how to prevent this in the future?

[Jacana]

Yesterday another prop fell off its been 18 months since the last one and guess what ,2 days ago while diving under the boat, as I regularly do ,I checked both props for tightness and fishing line etc.and both were okay ,can we get a current update of lost props from the sd20 legs as its time for Yanmar to rectify this situation before we have a serious incident.I use my boat almost daily and this time I was coming into my berth on my pontoon when I reversed the port motor to assist in stopping,panic stations when nothing happened.Thankfully I got a line onto a cleat before kissing the wall.Initially suspected a gearbox malfunction until I checked the saildrive.Need a prop shaft with a locking pin through the spline,perhaps Yanmar can assist all us sd20ers.Geoff.

[Laidback]

Has anyone got a decent graphic or photo of the SAD 20 prop shaft --
Found some line drawings YANMAR Diesel Power - Saildrive Series Marine Engines

[Jacana]

Just came across an article in a discussion in the FP Belize thread:

" I must have lost more props than anyone (I think 4 in 6 years)! Blize hull #91. But I finally have a solution. Sea Hawk (from down under) makes a locking nut system for the Yanmar SD20. It includes a castle nut and the centre bolt has holes in it. Sea Hawk includes a safety wire to fix the castle nut to the centre bolt, I modified mine to us 3/16" cotter pins. Haven't lost a prop for 3+ years. I got mine from Frank & Jimmie's Prop Shop in Ft. Lauderdale, Florida. (Reminds me I should order a spare!). "

This hopefully will fix our expensive problem,think about 87 lost props from SD20 saildrives on this forum alone .Now has anyone got a photo they can post and or information on how to get this locking nut system .Thanks Geoff.