orion
Full Member
Posts: 46
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Post by orion on May 16, 2021 10:12:17 GMT
Hi all,
I have a SO 32i with a 3YM20 engine. wish to change the gearbox oil but finding it difficult to get the specified transmission oil. The owners manual recommends API classification CD or better, SAE Viscosity #20 or #30. However finding it difficult to obtain this spec in motor factors or Marine Shop.
Other boat owners have recommended to use the same oil as the engine (engine spec:- API CD or better TBN value9 or more, SAE Viscosity 10W 30 or 15W 40). I use Mobile Super 1000 in the engine (API CF, 15W 40). It's only as I type I realise that that meets the spec but can i use engine oil in a gearbox?
A boat mechanic recommended 80/90 gearbox oil which i purchased but slow to use as the SAE viscosity is higher.
Your thoughts please.
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Post by vasko on May 16, 2021 10:19:22 GMT
Check with Yanmar - if the suggestion is same as engine then use 10w40 if proper gearbox oil - then gearbox oil
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Post by vasko on May 16, 2021 10:21:35 GMT
checked - my understanding is that the oil should be same as engine - my personal view is LIDL 10w40 - Mercedes certified - I put the same in my engine...
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orion
Full Member
Posts: 46
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Post by orion on May 16, 2021 15:08:16 GMT
Thanks for the reply Vasko,
To clarify, go with engine oil I beleive you are recommending.
O.
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Post by Chris Meyer on May 16, 2021 15:58:29 GMT
Check with Yanmar - if the suggestion is same as engine then use 10w40 if proper gearbox oil - then gearbox oil I just looked at the Yanmar manual for our engine which includes yours. I am not sure but am suspecting your gearbox is a saildrive like our 3ym30. Yanmar recommends 80-90W. See page 21 of 231 of the manual. This is much higher viscosity than normal engine oil. |
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Post by vasko on May 16, 2021 16:41:25 GMT
Check with Yanmar - if the suggestion is same as engine then use 10w40 if proper gearbox oil - then gearbox oil I just looked at the Yanmar manual for our engine which includes yours. I am not sure but am suspecting your gearbox is a saildrive like our 3ym30. Yanmar recommends 80-90W. See page 21 of 231 of the manual. This is much higher viscosity than normal engine oil. YES 80-90W is very different from engine oil - if this is recommended by yanmar then this should be the choice |
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orion
Full Member
Posts: 46
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Post by orion on May 16, 2021 19:00:46 GMT
/ or Hi
It's NOT a sail Drive but the manual mentions 2 options of gear box but I believe it's a KM2P-1. Must see if there's a plate on the box.
The manual does include a spec for a Sail Drive of SAE 90 or 80W 90. But since it's NOT a sail Drive I am slow to use the 80/90 gearbox oil as recommended by the boat mechanic.
Thanks for your help.
O.
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Post by Syrah on May 17, 2021 4:32:51 GMT
I worked 40+ years in the oil industry, including international roles in lubricant development. They are saying that viscosity is the only important property and that it should be a non-multi grade oil of SAE 30 grade. Multigrade oils have polymers in them that alter how much the oil thins when it heats up. They are saying that they don’t want it to have polymer in it. You should be able to find a mono grade SAE 30 grade engine oil that will meet the recommendations. This is the one I’m using. Hope this helps Wayne  |
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Post by Trevor on May 20, 2021 22:01:59 GMT
Hello Syrah,
Is that mono grade engine oil your recommendation for the engine or the gearbox? I am keen to know what is the preferred oil for the engine. Should it be multi grade or mono grade?
Regards
Trevor
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Post by sitara on May 20, 2021 22:09:12 GMT
My diesel mechanics, a Yanmar supplier, sell Yanmar oil which they recommend I use in my boat. It is a 30 monograde oil and is used in engine and gearbox. Syrah trust the cruise north is going well. Rob
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Post by Syrah on May 20, 2021 23:19:09 GMT
Hello Syrah, Is that mono grade engine oil your recommendation for the engine or the gearbox? I am keen to know what is the preferred oil for the engine. Should it be multi grade or mono grade? Regards Trevor Hi Trevor, It’s the manufacturer’s recommendation to use a monograde oil for the gearbox rather than being my specific recommendation. My aim was to try and provide a bit of guidance as to what that means. For the engine in our 42ds, I personally use a 15W/40 (i.e. multigrade) oil from a reputable supplier. I believe 15W/40 is Yanmar’s recommendation, although I couldn’t find the page in the service manual that I have with me (pdf) that specifically says this. The one I am using at the moment is API CJ-4, which is a much later spec than what was in place at the time the engine was made. These later spec products, in general, cover the requirements of the earlier specs. C classifications are for Compression (diesel) engines, S classifications are for Spark (Gasoline) engines. If you are interested in what these specs mean, the definitions are shown here. www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-diesel-c-categoriesThe best protection really comes from keeping the oil at the correct level and changing it at regular intervals. Hope this helps Wayne |
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Post by Syrah on May 20, 2021 23:22:42 GMT
Thanks Rob (Sitara). We are doing very well. A 42ds really is a great boat for an extended trip. Missing the winter cold weather is the best part. Regards Wayne
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Post by Trevor on May 21, 2021 2:31:59 GMT
Thanks Rob and Wayne,
Good to get the “good oil” on good oil. I investigated multi grade oils back when I was a kid and really into car engine wear and it actually became quite complex. Back then I was into Penns Oil but I was wondering what the modern thinking was with regard to premium oils for my beloved Yanmar.
Thanks again for the information.
Kind regards,
Trevor
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