Prop Fell Off! Help!

[ssullivan]

Anyone know why my new Yanmar SD20 saildrive prop fell off today?

I had a fantastic day sailing up the Chesapeake, and when I went to anchor, I had no thrust from my port saildrive in forward or reverse. A quick check verified that my prop is gone!!

It had been loose at my last haul out (only a week or so ago!). When I put it on, I did the following:

1) Put locktite anti-seize on shaft, bolts and everywhere there are threads

2) Tighten everything up quite tight, as they had been loose before.

How could a prop just come loose? What should I do? Any tips at all??

This is pretty expensive considering I haven't got many miles between them loosening up.

Also, where can I get this part real REAL fast so my wife doesn't freak out? We have a timetable (not for weather, but for when there is good weather, and this is bad because it's Sat and everybody is closed.)

I'm in the C&D Canal in Maryland. HELP!

[sluissa]

there's a cottar pin that goes through my outboard prop bolt... could this have been left off? just an idea, I have no clue. Sorry about your loss. You didn't do anything to upset any of the "higher ups" with this boat, did you? (Throw a stone over it? Change the name without the right ceremony? etc.?)

[ssullivan]

Hi Sluissa,

Thanks for the reply. I know about those cotter pins on outboards. The saildrives don't have that. All they have is a single, rather thin allen bolt that holds the cone and prop in place. My bolt, the cone and prop are all gone! Vanished today when we were sailing like crazy up the Chesapeake.

Na... I don't think I upset any higher ups. I haven't had many real problems with the boat. If you take a boat on a couple thousand mile trip, things happen. So far, I would consider my luck as being very good, actually. A lot of people have had a lot worse initial deliveries than this... I'm thinking of some poor folks I know who had to repower on their delivery home. Ouch!

[AnchorageGuy]

Sean, See if you can call our friend Ken Broman at Oak Harbor Marina on Rock Creek. He is quite a bit south of you but knows everyone on the bay. His number is 410-255-4070 and he should be able to hook you up. There is a marina that does service work not far from you but I can't remember their name or exact location. Did bot spend that much time at the north end. Tell him Chuck and Susan gave you his number.

[CarlF]

Call Mack Boring (the Yanmar distributor for the north east, mid Atlantic and Great Lakes). They will try to help. I've known them to drive parts down to people. At a minimum they'll grease the skids at a local boatyard. I think they might even treat this as a warranty issue (especially if you don't act like a jerk and look for sympathy on the wife issue). The problem will be raising anyone on a weekend. Try the main number in New Jersey - 908-964-0700. If that fails try Michigan - 847-526-9700. Bob Schroer in Michigan helps out boaters in all of Mack Boring's regions.

Carl

[cchesley]

This seems to be a not uncommon occurance for sail drives. I've heard of it more than once and several times on the same boat. Cause unknown. What kind of prop do you have? My flexofold prop has a little washer that must be bent over to lock the locking nut to the primary nut.

Hope you can get a new prop okay.

[Steve Rust]

Mine has a large 24mm castle nut that holds the prop onto the shaft and over the top of the nut is a locking washer that has a tab
that fits into a keyway on the shaft. Other tabs fit into slots on the nut and it locks the whole thing in place. You must be missing some critical part.

[maxingout]

When I was in American Samoa, one of my friends lost a maxiprop off his starboard engine. He ordered a new one and sailed to Tonga where he planned to install it. When he arrived in Tonga, the maxiprop had fallen off the port engine as well. Both engines were saildrives.

It turns out that he was supposed to have a pin though the prop and the prop shafts. He had resisted the idea of drilling his prop shafts and installed the maxiprops without drilling and inserting the pins. It cost him two props. That was more than a five thousand dollar mistake at the time.

[Alan Wheeler]

Sully, I take from what I read of your post, you have a tapered shaft connection. The issue will have been that you have placed anti-seize on the shaft. What happens is that the two tapers come together as a flat surface (opposite pair's remember). When the two pairs come together, they don't squeeze the excess out between them. So the greasy stuff hydraulicly keeps the two surface separated and after a short while of spinning in the water, the prop becomes loose again. It is actually better to leave the two surfaces dry and clean of anything. When everything is tight, water can not get in anyway, so it won't seize. As for bolts etc, if you want to use anything, use a low strength thread locker from loctite. The product holds the nut or bolt and also acts as an anitseize by keeping water out of the mating surfaces.
Most likely, the prop wouldn't have fallen off right away. Where did you last put the engine in reverse, That will most likely be where it dropped off. Can you dive the area to see if you can find it??
Check the other prop to ensure it is OK. You don't want to loose two.
So how hard is it to steer a cat with one motor??

[David M]

That's just nuts..pardon the pun. But castle nuts are not just for outboards, my 330 Hp diesels have them holding a 24" x 24" prop onto the shaft. Whoever thought it would be better not to have a castle nut and cotter pin?

[David_Old_Jersey]

Not saildrives, but down here not unknown for a few Marina based boats to lose props due to the effects of ELectrolysis....as you were talking Anode problems before maybe yer did not get away with it as you thought?.......in which case I would be thinking a lot about the other prop........however given you previous comments on the PO may well be that both props were not correctly fixed on / correct fixings, and if you simply replicated what you had already..........

Can you get a looksee at a manual?

[ssullivan]

Thanks for the information.

The factory spec has only an allen bolt, a prop cone and then the propeller (you can see it that thread entitled "Yanmar SD20 CAUTION!!" on this forum. I posted the schematic up there (courtesy Tellie).


The shaft is just like an outboard (I think this is the taper shaft Wheels is talking about).

To be safe, I plan to do as Wheels says and put some locking locktite on there. I had put the other type because I had heard how hard it was to get the props/bolts off. Apparently, if a good day's sail (6-8 knots for 10 hours) can do it, it's not that hard. ha ha


So I'll put on that locktite. Also, I was planning to get stainless steel lockwashers for the bolt as well.

Steve Rust: My saildrive definitely does not have any of what you are describing. I have the components in the little "optional" box on the exploded diagram in the "Yanmar SD20 Caution" thread on this forum. I think you are describing the components from the standard SD? Are these in some way better?

Thanks again.

[SeaKing]

Sean,

I am 15-20 minute from Chesapeake City, in Galena at Georgetown Yacht Basin. Pulled my saildrive gearcase seal's today, both sides. I am on the boat tonight, plan on working on a few things tomorrow.

I lost a prop last year, had to use scuba gear to put one on at my home dock.

I too had been have a brisk day of sailing when that happened, my nephew had been at the helm all day. After we rolled in the jib told me the stbd engine wouldn't go in reverse. So he started the port engine and he said it didn't seem to go in gear. After checking everything out we had lost the prop on the port side and reverse went out on the stbd side. Try docking a 27' wide catamaran with only one engine and no reverse. Just took it easy, one shot in, lines were on the dock ready to pick up, went perfect. For a second I was happy then remembered , no prop, no reverse, had to buy a prop and figure out why I had no reverse.

You can get a different prop nut instead of the cone. A regular nut and an allen key bolt in the center of it. I think you can tighten the regular style better. If you look on the parts breakdown you can see it.

Are you in Chesapeake City?

[ssullivan]

Hi SeaKing.

I just send you a PM.

[Strygaldwir]

SeaKing. I am also in Shady Side Maryland! It isn't that big a place, I haven't seen you yet. I'll have to keep a look out!

By the way, where do you have your boat hauled? Most folks are telling me Baltimore, or Solomon.