Craftsman oil wt.

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mecompco

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So before I started reading the forum, I filled all the oil cups/holes on my 101.07383 with Mobile 1 synthetic gear oil. I now find that 20 wt. is recommended. Will this cause problems? Have not really run the lathe other than making sure it spins. I will pick up some 20 wt. for future use. Thanks!

Regards,
Michael
 
I do not think it will cause any problems. Any oil is better than none. But try and fill oil cups with that 20W. So it will work its way to the bearings. I use 30W mobile 1 thomas s
 
Michael,

The Mobile 1 won't hurt anything short term but the reason for the recommendations to use straight mineral oil and not to use current high detergent engine oils is that most if not all synthetic engine oils contain detergents and absorb and hold water. Not a problem in IC engines as the oil gets hot enough to evaporate the water but in machine tools, and especially those that sometimes spend long periods not being used, it will cause rust in all but the driest climates.

SAE 20 marked as such has gotten quite difficult to find. The only source I found in Houston was 3-in-One in the little squirt cans, In the quantity used on a lathe it would be quite expensive. About 3 years ago, I bought a gallon of Mobile DTE Circulating Oil Hevay Medium ISO 68 from Enco. SAE 20 W crosses to ISO 65 to 70, depending upon whose chart you are looking at. Two or three machine shop suppliers in Houston also carry it but I was ordering some other things from Enco at the time.

Robert D.
 
Thanks for the responses, guys. Not sure if gear oil has detergents? Probably. I thought the problem might be the viscosity (75-90) that might be too heavy to flow properly.

Will see what I can find for non-detergent oil before I run the machine to any extent.

Regards,
Michael
 
Sorry. I assumed that you meant Mobile 1 10W40 (or something similar) engine oil. SAE 75W90 is a little thick. I don't know whether it contains detergents or not. But I would recommend putting a rubber tube or hose on each of the oilers and blowing through it. The various oil passage holes are small and the heavier gear oil may or may not flow through them. If your spindle bearing oil cups have the later or retrofitted felt plugs, I would pull the plugs and blow through those cups, too. And washing out the felts. Then with the felts out, fill the cups with 20 W and let it drain through once before replacing the felts.

Robert D.
 
wa5cab said:
Sorry. I assumed that you meant Mobile 1 10W40 (or something similar) engine oil. SAE 75W90 is a little thick. I don't know whether it contains detergents or not. But I would recommend putting a rubber tube or hose on each of the oilers and blowing through it. The various oil passage holes are small and the heavier gear oil may or may not flow through them. If your spindle bearing oil cups have the later or retrofitted felt plugs, I would pull the plugs and blow through those cups, too. And washing out the felts. Then with the felts out, fill the cups with 20 W and let it drain through once before replacing the felts.

Robert D.
Click to expand...

Gear oil SAE viscosities are not the same as engine oil SAE viscosities. 75W90 gear oil is actually similar in room-temperature viscosity to 10W40 engine oil.

I think it's better to refer to ISO grades when specifying oil for machines, though. The SAE grading system is very application-specific.
 
wa5cab said:
Sorry. I assumed that you meant Mobile 1 10W40 (or something similar) engine oil. SAE 75W90 is a little thick. I don't know whether it contains detergents or not. But I would recommend putting a rubber tube or hose on each of the oilers and blowing through it. The various oil passage holes are small and the heavier gear oil may or may not flow through them. If your spindle bearing oil cups have the later or retrofitted felt plugs, I would pull the plugs and blow through those cups, too. And washing out the felts. Then with the felts out, fill the cups with 20 W and let it drain through once before replacing the felts.

Robert D.
Click to expand...

Thanks for the clarification, Robert. I don't think there are any felts in the cups. I did noodle around with the machine a little this afternoon and it looks like the oil is flowing from the cups--the small holes, I don't know. I will def. find the proper lube ASAP.

Regards,
Michael
 
OK. I had forgotten how thin 75W Gear is compared to 90W Gear. 90W Gear ~ 50W Crankcase but 75W Gear ~ 15W Crankcase.
 
The spindle in that lathe has sintered "Oilite" bronze (SAE 841) bushings supporting the four-step pulley. When operated in back-gear mode the spindle turns inside those bushings. Similarly the counter shaft is supported by sintered Oilite bronze bushings. Oilite bronze is porous and impregnated with SAE 10 (early) or SAE 20 (later) non-detergent machine oil when manufactured. While operating, as the sintered bronze bushings warm they "sweat" oil to maintain lubrication of the rotating shaft. When the machine is stopped and the bronze cools it absorbs free oil back into the pores.

Although the spindle main bearings are Babbit and not Oilite Bronze, there are no oil seals to contain the lubricant and there will always be some bleed-over between the main bearings to the pulley bushings. To maintain compatibility with the oil in the bushings you should be using either SAE 10 or SAE 20 non-detergent oil and nothing else.

Four years ago I bought a 2 gallon jug of SAE 20 non-detergent motor oil from a nearby Tractor Supply store (www.tractorsupply.com). I figure it will last longer than the blood in my veins.

If the local big-box auto parts store doesn't have it or can't get it you should be able to find it at most any NAPA auto parts store. As a last resort let your fingers do the walking on the keyboard and use your favorite web search engine to find a suitable supplier.
 
Spiral_Chips said:
If the local big-box auto parts store doesn't have it or can't get it you should be able to find it at most any NAPA auto parts store. As a last resort let your fingers do the walking on the keyboard and use your favorite web search engine to find a suitable supplier.
Click to expand...

Ditto that, I usually order lubes from Enco when they have free shipping offers... think they have one going on now...
 
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