alan bechard Posted August 22, 2005 Report Share Posted August 22, 2005 Throwing out some general rules here, but usually, if a bottom end oil is intended for two strokes they will grade it with a different system than a 4 stroke. Soooo, when you go pick up a bottle of two stroke lower unit oil (clutch) it will say something like 75 wt. or 80 Wt. And if you are picking up an oil for a 4 stroke, it will be speced with the "standard"(SAE) designation of 10W40 or 10W30 or so. As I am looking to help by brother in Law in Germany find the right lubricants for his bikes, I am stumbling into that the European's are flagging all their transmission type oils with the SAE grades Ie 10W40 or so... SOOOOOOO, my question is, On the bottle of oil that you guys are using in the lower unit / transmission / clutch of your two stroke machine, what spec does it say 10W40 or 10W30 or such or 75wt or 85wt or such??? Thanks. Quote Link to comment Share on other sites More sharing options...
ronm Posted September 1, 2005 Report Share Posted September 1, 2005 Al, Sorry but I just found your post. Here is what I think I know. The SAE has a group of numbers that are used to designate ranges of viscosities for engine oils. These are the common SAE 30, SAE 10W40, etc that we are used to seeing in engine oils. The numbers do not directly correspond to physical properties in the way that viscosity units such as centistokes or saybolt universal seconds do. A committee in the SAE just decided that SAE 40 oils would have a range of viscosities from .... to .... at a temperature of .... They used a different group of numbers for gear oils. These are typically 80 to 150. I don't have a book handy tonight, but I believe SAE 75 gear oil is a little thinner than SAE 30 engine oil. Strictly speaking, there is no such thing as SAE 30 or SAE 10W40, etc gear oil. These designations must have been coined for sales purposes. As for 2 stroke gearboxes, most clutches work better with thinner oils. I just use SAE 5w20 engine oil in my Beta although lots of people like the SAE 75 and 80 gear oils. The SAE 75 Maxima product is about the same viscosity as Amsoil synthetic ATF (check out both websites for specs). BTW, we missed the Clarksville clan at the Whooping Creek event. Hope to see you at Shooting Creek Quote Link to comment Share on other sites More sharing options...
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