440: Anyone replaced their SD 50s?

[Nahbrown]

I think we just lost one today and will have to have a service rep investigate the CRUNCH sound and why the engine died immediately following the loud sound.


I understand SD 50s are replaced with SD 60s now. Has anyone done this? Where did you have it done, and what was the cost?


Thanks

[Bean Counter]

A number of people have replaced the SD50 with SD 60. There is an adapter plate available from Yanmar. The early SD 60s had problems of their own, subsequently fixed. Last I heard the SD 60 was about $7000 in Maryland for the unit + adapter +labor. I was tempted to swap our SD50s out but then I learned how to lap the cones, and so for 4 hrs of my labor once every couple of seasons I saved a lot of money. The cost really starts to rocket when service providers start spinning stories about having to remove the drive take it to the workshop, blah blah blah, so then your boat is sitting on the hard with a hole it it, at the mercy of the shop, so you pay for the haul out, the yard space, and any other costs like rental cars, airfares or motels and so on. So I would want to make pretty sure the drive is a write-off and not just a worn clutch cone or maybe a damaged gear set.


Start with the top of the unit while boat is still in the water, can check the clutch, shafts, and top gears and bearings. IF that shows no damage you will need to get hauled to inspect the lower gear housing at the prop, prop and lower shaft and gear set is easily removed and inspected. If still a problem inside the leg, that is when it may need to come off and then the clock will start running expensively.


Oh before all that check that something has not wrapped itself around the prop like a cable or chain on a fish/crab trap, this will cause the engine to stall.

[OldGreyB]

Here is a copy of the Yanmar Service Bulletin YMTQTB13-022: Notice of Replacement of SD60 from SD40& 50.

Could be of use to you when scoping / discussing work execution with your marine provider.

[Dockhead]

Originally Posted by Bean Counter

. . . Oh before all that check that something has not wrapped itself around the prop like a cable or chain on a fish/crab trap, this will cause the engine to stall.

This! This is a much more common cause of the described symptoms, than sail drive failure.

[adjo]

Originally Posted by Dockhead

This! This is a much more common cause of the described symptoms, than sail drive failure.

And this is one reason my SD50 is fitted with a Kiwi Prop. The plastic blades are likely to absorb much of the energy. They are inexpensive (relatively) and can even be replaced while the boat is afloat..

[Jenta]

I haven't done it on our 440, but the yard we were at last October did one on a Lagoon 420 while we were there.

The yard was Zimmerman Marine in Matthews Virginia (actually Cardinal) and their prices for the haul out and yard fees were very reasonable and they have a trailer for hauling out cats instead of a sling which is very nice.

So you may want to get a quote there if Virginia is in reach for service in your time frame. Obviously if you need it done sooner than later and you're not already there that will be a chilly one for a few more months.

But at least you can get a good reference quote from someone that just recently did one.

[Nahbrown]

Thanks for the responses. A line had indeed fouled the prop.

[Jenta]

Good news!