Bowthruster and main propellor seals

John and Anne on Bali Hai <annejohnholl@...>

Hi Barry and Robyn,
Thanks for the seal numbers.As Jean Luc says the bronze bearing on the main prop shaft is not really a bearing and has to be changed every couple of years or so. A replacement is from Amel, they call it a wearing ring and it is expensive. If the boat is still out of the water you should remove the propellor and the plug keeping the oil in.Drain the oil out and use a pump to get the oil resting below the propshaft. If the oil is whitish then sea water has been getting in. I changed mine two or three years ago and I cannot recall what actually wears but you should be able to see it. I took a new one to a machine shop here in Malta and had another made up thus saving the shipping cost etc. and I suggest you take the old one into a shop in Oz as my experience was that it was much cheaper to have one made up than getting one from France. I recall thinking that perhaps the worn part could have been built up but I did not enquire. My machinist wanted to make the new one in phosphor bronze but I do not know whether he did.
This subject was covered on this site six or seven years ago and one good tip was to drill a hole either side of the old oil seal, screw in long wood screws and use those to pull the seal out and repeat with the next two. Another good tip was to use the old wearing ring to drive the new one into place.
So far as the bow thruster is concerned you will find that the new prop mounting ring is a very tight fit but if you use two machine screws longer than the new nylon ones you can line up and then pull the ring far enough on to start using the nylon ones. I have fitted a new prop with the unit still in place in this way using scuba kit. Alternatively Amel make up a simple kit so that the unit can be lowered right out of the housing and left hanging on a line so that the unit can be taken on board. This technique means that you have to be careful to rinse off all salt water,dry and use waterproof grease before reuniting the unit with the motor so that it does not rust and seize in place.

Best wishes, Anne and John, SM317

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