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Trying to find the correct gear oil for my apron
- Thread starter ltlvt
- Start date
Holy crap... I don't know this one, I hadda go look. That is top shelf. A quart of that is still priced better than a gallon of line wash... You're smiling from every direction.
It's very closely related to the kinematic viscosity(centistokes, or cst) at 40c. Just like the SAE system, modern oils have blown that outdated system right out of the water. You think ISO is hard to wrap your head around, try SAE 5W-30. The kinematic viscosity of that is all over the map, but the dynamic viscosity, or the high temperature, high shear viscosity (actual in use behavior), those viscosities goes all the way from water to rear diff oil, literally on both ends, on what we used to call a "light" oil. And I doubt the rules are gonna change soon, because there's no one left in the US making chisels good enough to carve a new hirogliph in their cave to tell the workers how to test to any standard that applies to modern oils or machines.
But I digress, I'm gonna get on a tangent, a rant, and probably a drinking binge...
Anyhow, the ISO rating is very near to the kinnematic viscosity at 40C. So instead of the SAE ratings, which have gone from good, to mediocre, to almost meaningless, the ISO relies on you picking the 40C viscosity in centistokes, and a viscosity index. Versus the SAE asking you to choose one or two arbitrary numbers, that Were good, but have gone by the wayside MANY years ago... Not oil company shmoo, but government shmoo. They HAVE to label their products based on an obsolete system. So with SAE, Material spec's (The factory spec number) rules all. WSS-M2C691-B1 for example, for some Fords, or MS-6395 for Mopars (FWIW, Oil can't fix that.
), or CES 20086 for some Cumminzes. Every auto maker and/or engine builder has their own spec. Most big machine and equipment have their own specs, or sometimes they select somebody elses. Years ago, it was more common to just spec a product that was correct. Nobody then knew how much the constand changes and updates in lubrication needs and lubrication technology was going to be so geometrical. It's nutz. The ISO thing is kinda the "metric" version. It works much better, it's more reflective of the actual product, it gets the same answers, but you just gotta go about it differently.It's kind of a heavy gear oil. Big, industrial high horsepower stationary transmissions and gear boxes, Massive screw and roots style air compressors and blowers. ISO 22, 32, and 46 would be "light" gear oils (although they go much lower). The number comes from the viscosity (with caviats), but rule of thumb is lower is thinner.
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when I had my South Bend lathe, the apron oil was Mobil DTE medium viscosity. not sure why his would need 90 wt gear oil. hope it doesn't get cold there LOL. my new/old lathe has automatic oiling of the ways plus a plunger oiler to get more on the ways if you want it and so I use a ways oil in the apron. Mobil Vacuoline 1409.
I had the same questions when I purchased my post WWII Sheldon military lathe.
John Knox (RIP) who worked at Sheldon and knew it all, told me SAE 30 machine oil everywhere (except the ways, natch).
Common sense, to think that whatever oils were specified 75 years ago for old 'Merican iron are certainly adequate but there are probably better choices in today's age. I think there's a tendency to get deep in the weeds as well, lubrication in many applications such as home shop engine lathes shouldn't be rocket science IMO. You shouldn't use way oil for lubricating spindle wicks, nor spindle oil on the ways. JMOYMMV
John Knox (RIP) who worked at Sheldon and knew it all, told me SAE 30 machine oil everywhere (except the ways, natch).
Common sense, to think that whatever oils were specified 75 years ago for old 'Merican iron are certainly adequate but there are probably better choices in today's age. I think there's a tendency to get deep in the weeds as well, lubrication in many applications such as home shop engine lathes shouldn't be rocket science IMO. You shouldn't use way oil for lubricating spindle wicks, nor spindle oil on the ways. JMOYMMV
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Normally it is not recommended to use automotive oils as circulating oils in machines as there are different properties, operating temperatures, friction modifiers, emulsifiers, etc. There is also the issue that some extreme pressure additives damage yellow metals, although this is less likely to occur with the new EP additives that activate with temperature.
This is inexpensive SAE 90 ISO 220 gear oil, I use Miles oils and they perform well and are much more reasonable then the big brand (Mobil) types. This is a full synthetic which tend to keep a bit more stable viscosity over a wider temperature range.
Alternate is Lucas gear oil, although is is a used in differentials, it does not attack yellow metals and is inexpensive. Apron is low moving gears under light pressure, so not a very demanding environment. Changing you oil on a regular bases and keeping debris/chips out of the carriage is the most important part.
This is inexpensive SAE 90 ISO 220 gear oil, I use Miles oils and they perform well and are much more reasonable then the big brand (Mobil) types. This is a full synthetic which tend to keep a bit more stable viscosity over a wider temperature range.
Alternate is Lucas gear oil, although is is a used in differentials, it does not attack yellow metals and is inexpensive. Apron is low moving gears under light pressure, so not a very demanding environment. Changing you oil on a regular bases and keeping debris/chips out of the carriage is the most important part.
when I bought my old South Bend (my 1st lathe, I went thru everything and replaced the oil wicks. the apron was absolutely packed with chips and black gunge. I was told that it was likely from someone using compressed air over a long period if time to clean the machine.
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If you want to bounce off into the esoteric about oils ask the fellows on the vintage tractor boards about the topic. Or about synthetics too.
Yikes.
They will rattle your teeth. And minds.
@yota
I get your distaste for the black gunk and chips.
More interesting to me tho is how were the ways?
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I had honestly thought about using 80-90 wt. but the damn ISO thing threw me off. It kind of seems like another way to force market their products. I chose the Mobil brand because Mobil 1 5w-30 wt is what GM recommended I use in my Corvette LS-1 motor and my 4.3 in my GMC Envoy. I expect the lubrication markets are much like the software industries. Forced obsolescence. There should be laws protecting us from the pirates. Thanks, mksj for bringing this subject down to my level. User friendly is also becoming of less value now days. I experienced that when I bought my first VFD.
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You want to use machine oil,not motor oil
the ways were pretty good for a 70-year-old machine. also, I did the spindle bearing check that was in the South Bend manual and it was still within spec.
