Volvo Folding Prop has 'fallen off'

[capbuckandpippy]

We have had the unfortunate experience of losing our prop. After a magnificent day sail we motored into an anchorage, dropped the anchor and reversed slowly back as we laid out the chain. Suddenly we were not going backwards any more. There was an unusual thunk as the prop went into reverse. We always wait in neutral for a space before going from forward to reverse. Now all we are left with is a very clean screw thread on the end of the propeller shaft. A search of the bottom has not found our prop in amongst the weed and its just a little too deep to get there on a free dive. Does anyone have any ideas of what could have caused this loss? The prop was fitted new in 2008 and has done around 900 hours since then, been hauled out and checked twice in that time and been on the hard stand for a total of 18 months as well.

Any clues anyone????

[roverhi]

Did ypu have a prop shaft nut zinc. If that got eaten up and cotter pin as well, the prop nut could have backed off or even broken off from electrolysis. Then there is the classic where whoever installed the prop just didn't put a cotter pin in it. In any case, it's will be an expensive replacement if you can't find someone with scuba gear to dive and search the bottom. Sorry to hear of your misfortune.

[capbuckandpippy]

Well here we are again with some good news.

We took a long and lat when we lost the prop and sent a diver down who located the prop on the bottom within 15 minutes. All in one piece including the nut and washer which do not appear to have any method or space in the internal mechanism to install a cotter pin.

We are replacing both the nut and the washer, have sent for new parts and are waiting to see what arrives.

The Ormaggiatore team at Cala di Medici Marina have been awesome in their help to us.

[Cotemar]

capbuckandpippy,

Maybe this link will help.

http://www.cruisersforum.com/forums/...tml#post803465

[SkiprJohn]

Happy news about recovering your prop. If it is a Gori prop it seems to be a pretty common problem. I haven't used mine yet since I am not in the water since I bought it but it has a threaded hole at the aft end for a jam nut to be installed.
There is no way I can see of installing a cotter pin so its not quite like most props.
kind regards,

[SkiprJohn]

I only say it is a common problem with the props that may not have been checked recently or installed improperly.

[hugosalt]

When I purchased my Flexofold prop I had the yard install it
because I wanted it installed right... when I pulled boat for the season prop was loose...lucky didn't loose prop.
They did not install locking washer/tab washer that came with the prop. I reinstalled prop with tab washer and a lot of red
Loctite. (can remove with heat)
Prop still there into 6th season.

[capbuckandpippy]

Hello Hugosalt
Yours is the closest reply yet to our situation except not sure if you have a sail drive or a shaft drive? Please can you confirm.

There is a locking washer with our prop which would work well with a hexagonal shaped nut which is shown in the Volvo drawings, but the big bronze nut which came up inside our prop is round, screws directly on to the shaft, with an inox washer in between which has two edges folded back which the screws fit into from the outside so not sure how this works on a round shaped nut - no surface to lock on to?

Does this sound familiar to you?

[DeepFrz]

Has anyone tried Nord-Lock washers on their prop nuts?

Nord-Lock wedge-locking washers

[capbuckandpippy]

Remember that we are a shaft drive, not sail drive. Most of the replies to date have been from people with experience with sail drives.

Today we spoke to a Volvo parts company in the UK who were able to throw some light on our dilemma. This is what we were told.

"There are so many different shaft sizes that Volvo do not supply the nut and washer when supplying folding propellers to shaft driven boats" It is the responsibility of the shaft manufacturer (if a new shaft is being fitted at the same time) or whoever fits the propeller, to supply the nut".

Oh great is our response! In good faith we buy a new Volvo folding propeller and a new shaft from a Volvo agent (in Slovenia who shall remain nameless,) and we are at the mercy of the local shaft manufacturer to make a nut which will ensure our propeller will stay attached to our boat! This is all news to us. And this is why our propeller fell off, because we have a smooth round nut, not a flat sided one.

However, we are stuck with the nut now as are sitting in an expensive marina in Italy and must get the whole thing put back together and move on. We took the prop and all parts to a highly recommended engineering shop in Livorno. We asked them to make us a new nut. Not necessary they say. Use the existing one with plenty of "Locktight" and screw the grub screws directly into the side of the nut - hard. Leave the inox washer out. It is enabling the nut to unscrew.

[hugosalt]

My Flex o fold hub was approved by Yanmar to be installed on my Yanmar SD 20 saildrive.

Does it make sense for your machine shop to grind flat one side
of the smooth round nut...enabling you to install/bend a
tab washer. Again based on almost losing my prop...can't emphasis enough...red loctite installed on clean threads.

[SailFastTri]

There should be two set screws in the side of the hub that secure the prop nut. They should be doubled with one driven down on top of the other, and blue locktite should be used liberally on them, or blue on the inner one with red on the outer one.

[vientoman]

Decided to use this thread as a means to request compatibility possibility: Since it involves volvo folding props, perhaps it is relevant.

is it possible to determine if the following volvo folding prop would fit the Yanmar SD-20 ?

here's a few shots of the volvo prop and the SD 20 splined shafts under consideration:



see link below for forward view of volvo folder:

https://lh3.googleusercontent.com/-g...20folding.jpeg







the splined shafts have the same number of splines ( 17) and the diameter of the prop bore and shafts are same I believe.

[colemj]

As far as I know, Yanmar uses Volvo props as their standard folding prop.

Mark

[hugosalt]

I called Mack Boring, large Yanmar dist. here on east coast
when I installed my Flex o fold folding prop...from an approved list they gave me an ok to install. There was a technical bulletin from Yanmar of approved folding props...probably for
warranty ok. Call your Yanmar dist. for latest approved list or check/search on line for "Yanmar technical bulletin FST-B08-05 Aug. 2005" bulletin seems to be included in a Varipriop ad on line...but is from 7 years ago.
Your Volvo prop may fit but could void any Warranty.
My original fixed prop that came with boat new was a Volvo .