Missing Prop, Again!

[jeff.sailor]

I'm really giving this forum a workout since i started partnering on a Bavaria 38 this season... (with Volvo Penta D2-55 saildrive and 3 blade fixed prop)

Yesterday I motored out of the marina and shut the engine down for a day sail in very light winds.  When winds died i started engine again to go seek some wind.  Engine worked fine but no propulsion.  After determining that a) we were not stuck on a pot; and b) the transmission linkage was attached; I was left with the conclusion that we had thrown the prop.  Had to be towed back in.

Yard just pulled boat and sure enough, prop is missing.  But the even bigger surprise is learning that this is the third time this has happened on this Bavaria 38, circa 2004.  Huh?

Anybody ever hear of such a thing?  How do I make this the last time this happens?  Yard checked with Volvo Penta specialist and is getting prop mounting hardware and instructions from them, including using red loctite.  Presume they did all the same the last two times.  What gives?

BTW, when I was out there diagnosing the problem, how do I determine that the transmission is working properly?  No shaft to watch spin, so how do you know power is being transferred down into the lower unit?

Jeff

[Odysseus]

This is a common issue, 3 things I would recommend you OVERSEE,

Use stainless steel Unbrako bolts instead of cross head you can get more tension on them. (put "Unbrako" into google if you do not know what they are)

Use Marine locktite

Jam a block of wood under the hull to a blade on the prop so the prop will not turn when tightening more tension.

Hope this helps, If not you are a Friend of Volvo's for life.

Odysseus

[Symphony]

As already suggested, the cone needs to be as tight as you can get it, but make sure the washer is behind the cone. The centre allen bolt locks the cone. When new they have a lock sealant in the htread, and it pays to use a new bolt every time.

You may find a folding prop such as a Flexofold has a more secure locking system, but 3 or 4 times the price of a fixed prop.

[jeff.sailor]

Thanks for the instructions guys. One question though:  isn't there (or shouldn't there be) a cotter pin on this install to prevent the nut from backing off?

Jeff

[jeff.sailor]

Okay, found the page in the engine manual detailing prop attachment and see that there is no cotter pin.  Guess that's the role of the marine loctite that Odysseus mentioned.  Researching marine loctite I see that it's a 2 part epoxy which I imagine is pretty strong stuff.  How would you remove the bolt at a later time if you needed to remove the prop?

[jeff.sailor]

In looking over the parts manual for the bolt that holds the prop in place, I can't find any information re: it's size or dimensions.  Where do I find that info so I can get the right sized Unbrako bolt.  Thanks in advance for all your help guys. Jeff

[Nigel]

Use Marine locktite

Volvo Penta recommend LOCTITE 243 for the anode, so why not for this?

[Odysseus]

Suggest you do not use 2 pack epoxy that's if you want to get the prop off again.

I use Loctite 243 on cleaned out threads, also I use loctite 243 and unbrako stainless steel chamfered bolts for the anode as they come loose as well.

Just email or phone your local Volvo agent and ask for the length and thread size, its a shoulder bolt not all thread. They will have them.

Odysseus

[Steve Cronin]

Thanks for the instructions guys. One question though:  isn't there (or shouldn't there be) a cotter pin on this install to prevent the nut from backing off?

Jeff

No. If you use a new hex bolt to lock the cone and torque it to the required amount your prop will NOT come off u til you want it to.

I know that there is a lot of disbelief about using a new bolt but the small pellet of locking material (epoxy putty as it happens) in the drilling into the threaded part is vital to ensure security of the bolt. My boat is eleven years old and the prop is removed every winter to check mfor fishing line around trhe somewhat useless "guard" on the shaft. I have re-used the existing bolt on a few occassions but only after drilling out the old epoxy (needs a 2mm drill) and replacing it with freshly activated stuff before torqueing it home. Yes, a block of wood betwixt hull and prop is very useful but at Gouvia the laying up cradles have a cross-member in just the right place  to wedge a smaller piece of timber and there is plenty lying about

Steve Cronin

BTW This "Verification" code is almost an obscene suggestion!

[Nigel]

BTW This "Verification" code is almost an obscene suggestion!

Sooner or later, random letters are going to spell something obscene. Don't worry, you only have to do it for the first few posts.

[Steve Cronin]

Suggest you do not use 2 pack epoxy that's if you want to get the prop off again.

I use Loctite 243 on cleaned out threads, also I use loctite 243 and unbrako stainless steel chamfered bolts for the anode as they come loose as well.

Just email or phone your local Volvo agent and ask for the length and thread size, its a shoulder bolt not all thread. They will have them.

Odysseus

The original pellet in the drilling is two-pack epoxy putty so as long as you only CAREULLY replace this, you will be OK. Surprising how many people still deny that this is the original locking method and think that the socket screw is just a plain bolt! Incidentally, although similar in design, a "WedgeLok" bolt should not be substituted since these utilise a nylon insert which have been shown to have a greater failure rate than the ones with an "active" locking agent.

Ask a PROPER Volvo agent and he will put you right. Refusal to accept the above fact is the major reason for loss of props in saildrive units.

Steve Cronin

[Trundletruc]

Bav 36 MD2030/MS25Ssaildrive
I have to take off the prop every year because the pesky anode comes loose. This year I noticed that corrosion/wear on the inside surface of the cone meant that the central locking bolt was not actually touching the cone. I have solved it this year by making a couple of washers. Needs careful measuring to check this.
New cone for me next year.