Yanmar SD-40 gear oil change - Help!

[dougweibel]

I have a Yanmar 4JH3E with a SD-40 sail drive. The sail drive is due for for a gear oil change and I am changing it using the in-water procedure from the SD-50 operations manual. I have not found a manual for the SD-40 that describes a gear oil change procedure. I have the appropriate fittings and have tried both the (suction) pump-out method and the (foot pump) blow-out method, and even a combination of the two. The gear oil that comes out flows easily enough and after I get most all of the oil I can get I can hear air gurgling through the sail drive. If I wait a few minutes a bit drips down somewhere and I can get out another half ounce to ounce.

The problem is that the sail drive data plate says the capacity is 1.8 liters and the manual says that the in-water procedure should be able to get it all out except for 0.2 to 0.3 liters. I am only getting out 600 to 700 mililiters. I have done it twice now with the same results.

HELP! What am I doing wrong?

Thanks,
Doug
S/V Meri - Tartan 4100

[ChrisseH]

I have the same engine with SD50. I have no experience in the in-water method, but know that SD40's gear lube capacity is 2.2 liters and SD50's is 2.1 liters.

As you only have been able to get out 600...700ml maybe the pipe from your pump does not reach down to the bottom of the lower gear case?

[dougweibel]

Originally Posted by ChrisseH

As you only have been able to get out 600...700ml maybe the pipe from your pump does not reach down to the bottom of the lower gear case?

The SD-50 has a continuous passage from the upper fitting to the lower fitting and that is what allows for the "suck it out" or "blow it out" methods described in the manual to work. I have been told by another forum member that the SD-40 is the same, but maybe not? I know for the SD-20 the manual says it cannot be done in the water.

[casar]

Got a new SD40 to replace my SD50 for an overhauling. The seals of the SD50 are no good anymore there is water in the oil. My problem: I can't get the boat out of the water till next spring.
I am worried that the ingress water may corrode the lower parts of the gearbox. Especially when the boat is stationary and the water and oil separate.
My idea: to run the engine for a while with gear so that the Quicksilver earlobe and water will form an emulsion and then change the oil.
But I have read that you can not get the whole oil out until the boat is not on land.
Is is possible to suck the all the oil out with a thin straw or an electrical oil pump with a thin tube?

[bil56]

sorry, but the saildrive leg drains from the bottom, the only way to remove all the oil... and change the seals

[ggray]

SD20 here.

It looked like I was getting about 1/3 of the oil out; I refilled, ran lightly for 5 minutes and repeated the process maybe 8 times.

That cleaned the oil nicely.

[SailingHarmonie]

The more I learn about saildrives, the less I want a boat with one. Much less a boat with TWO!

[casar]

mmh, that depends on the situation I would say.
My one is installed in the back of a motorboat and it works really nicely. Now I found water in the oil and must do a little overhauling. After 20 years and 2300h. fair enough.