propellers coming off

[stevem]

In August I anchored in Porto Rafti in Greece. The anchor was buoyed. When I tried to weigh anchor next morning found it to be fouled and no amount of  trying to lift it , motor backwards or forwards would free it. I had to call a diver eventually. He found the anchor and the chain had fouled on old mooring tackle.  He also said that I had no propeller. I was able to get a  new prop through the help of the diver and local Volvo dealer.  I latter spoke to a French b42 owner who said he had lost two props and my insurers said they have had a number claims for the same thing. And yesterday I saw a thread on sailowners .com about lost props, all relating to Volvo saildrives. Its obviously a design fault. I think that quickly giving high revs astern is causing the central Alanscrew to unscrew.I had put locktight on the thread and it was a new screw fitted beginning of June when I changed the anode. I also lost my rope cutters. Total cost of replacement and labour was £1750. Luckily my insurers Bishop Skinner were brilliant.
Has anyone else lost a prop?

[Odysseus]

Hi Steve, yes I have been there and yes there is an issue with the Volvo fixed props as the bolts are not retained other than loctite 243.
If this is not applied to specification, and you jam a length of wood between hull and blade to tighten bolts, the risk is clear. However the newer Volvo folding 3 blade has retained bolts so far less a risk, the older Volvo 2 blade folding prop was very bad as you had to Align a blind dimple up with the retaining bolt, very hit and miss, lost one of those as well, long time ago.

Also the retaining bolts for the anode are difficult to tighten, I use hexhead bolts as photo.

My rules are, clean, dry, apply 243, rest for a few hours.

Hope this helps.

Odysseus
Bav 38

[Trundletruc]

Not had a prop come off - yet. But we changed the saildrive and luckily I noticed the locking bolt was bottoming in its thread before it was touching the actual locking cone. I had to file down some washers to go inside the cone so that the bolt could actually reach it.
The whole design of this locking bolt is suspect! If you have had trouble it might be worth checking?
Before putting a lot of pressure on the saildrive in reverse do you realise that only two small bolts hold the lower bearings in place? Something to think about but I have not heard of anyone pulling out the propshaft when in reverse.