Seeking "Best Practices" for Yanmar SD 50 Cone Slip

[psychfeld]

Hello all,

I've purchased a 2009 Lagoon 420 with two SD 50's nine months ago.

At month 8 one of the SDs started slipping. Stuck a long ways from home a mate suggested i replace the gear oil (I'd been using the Quick Silver, High Performance Lube from MercCruiser) with diesel motor oil 15-40.

I followed his suggestions given my predicament - new owner/operator, not skilled at navigating this cat on a single screw. I took the chance that further damage might occur and pumped out the old lube for 15-40 (I don't believe there is any damage, I've been running without slippage for another 40+ hours since swapping lubes).

To my surprise since swapping the gear oil in the slipping SD the unit has performed without slippage (at least I cannot detect it as I could before). Upon further online investigation of options I see the Yanmar replacement SD 60 no longer suggests this overpriced gear oil but instead authorizes diesel motor oil 15-40 as the recommended lube.

I would love to hear any suggestions you might have to remedy this apparent chronic problem. I wrote to a person who posted a fix (see Rework Kit) that includes replacing the thrust washers with thrust bearings.

Does anyone have any firsthand experience with this person's recommendations, he goes by panache@...com, I think his first name is Brett. I am eager to find an intelligent repair, that others have found to be successful. Private messages are welcome as fitting.

Thanks for the time/help.