Can I use gear oil in the headstock?

13" Leblond roundhead (1947). Seems a lot like a manual transmission in there, so I have to wonder if regular 80W/90 tranny oil will work?

borne2fly said:

if regular 80W/90 tranny oil will work?

Click to expand...

No No No No.

Use ISO 46 or 68 circulating oil, like Exxon Mobil DTE Medium or Heavy Medium.

John Oder

John,
I have to ask ..... what is the difference? Does ISO 46 or 68 mean 46w or 68w? I'm wondering what the relative viscosity difference is.
-Don

I have always wondered why a heavy tranny oil can work so well in a transmission but it is not recommended at all in a lathe headstock. Both are gearboxes, right? Again, just curious. Will the tranny oil cause the headstock to leak? What would happen?

borne2fly said:

John,
I have to ask ..... what is the difference? Does ISO 46 or 68 mean 46w or 68w? I'm wondering what the relative viscosity difference is.
-Don

Click to expand...

Nope, I suppose you could call it the metric version of viscosity..

borne2fly said:

I have always wondered why a heavy tranny oil can work so well in a transmission but it is not recommended at all in a lathe headstock. Both are gearboxes, right? Again, just curious. Will the tranny oil cause the headstock to leak? What would happen?

Click to expand...

Headstocks and the likes use precision bearings which have very fine tolerances.. Heavy oil will firstly not lubricate the bearing very well and also make all the bearings heat up and introduce errors due to thermal expansion and probably destroy bearings in the end...

borne2fly said:

I have always wondered why a heavy tranny oil can work so well in a transmission but it is not recommended at all in a lathe headstock. Both are gearboxes, right? Again, just curious. Will the tranny oil cause the headstock to leak? What would happen?

Click to expand...

as I undertand it, lubrication is always a matter of compromises. the concept is that thelubrication gets between the two metal objects andkeeps them from actually touching.

It needs to be thin enough to fit between the objects, and thick enough
not to get squeezed out. You can demonstrate the difference fairly easily
right on your lathe bed.----wait until the bed is fairly dry---notice how hard
it is to move the tail stock---particularly if you have a heavy one.

Now dump some 90weight on the bed.--- not much difference. you move the tail stock, the 90weight just pushes along the ways in front of the tail stock and it still pushes hard. --- now dump some light oil on the bed.... tail stock rides up on the oil and slides easily......

the automotive gear boxes have some pretty high pressures in them---consider the size of theh gear tooth and the torque.... and consider the potential for lighter lubricant being squeezed out.---but they are made with theh space for it to fit.

now consider the lathe---close tolerances, low pressures, the lubricant
won't get there in the first place.

---
the next question that always comes---is how about motor oil?

Well the answer to that is that motor oils now days all have detergents added to them. the concept of detergents is just like doing the laundry.
The detergent is designed to dissolve foreign materials (in an engine usually carbon/soot blowby) and other cruds that show up. they are dissolved and suspended in the oil. If you don't change the oil in your car eventually
the 'dissolving capacity' of the detergent is reached and then the impurities are only partially dissolved, and your motor oil turns into a gritty grinding compound, and pretty quick thereafter you need another car.

IN a lathe, the intention of the lubricant is to work like soap (as contrasted with detergent) It's just suppose to loosen it, wash it away, and let it settle out. That is a low tech solution, but you are also NOT dealing with
an engine that squirts some soot into the oil 16,000 times a minute (a 8 cylinder engine at 4,000 RPM) or maybe more.

Good info guys, thank you!
RC, I'm gonna nail that handy chart up in my shop.
I'm still not sure what the difference is between, say ISO 68 and SAE 80W gear oil. According to the chart above, it looks like they are about the same. I don't know if gear oil has detergents in it, I thought that was something peculiar to motor oil.

Another thought ..... are the only precision bearings in a headstock the spindle bearings? And all the other bearings are just standard grade? Because, in my machine the spindle only has two bearings (one at each end, no center bearing) which get their oil from "filler caps" above each bearing. It seems that the spindle bearings are lubed by whatever I pour into the filler caps, and the gears are lubed by whatever oil is in the headstock. Of course, whatever I'm dumping into the spindle bearings eventually flows down into the headstock.
Can this explain how a machine with high mileage and hideous sludge in the headstock can still have near-perfect spindle bearings ..... the bearings always saw "good" oil, not the sludge?

RC,
Am I reading that chart right?
Is it saying that ISO 68 = SAE 20 (crankcase) = SAE 80W (gear)?
Because I recall SAE 20 crankcase oil as being pretty thin, while 80W gear oil is pretty darn thick.

Just to add a further twist to the discussion -
When I was sorting out my '57 CVA (British version of a 10EE) I spoke to the local Shell rep, who told me that their Tonna slideway oil was designed so that it would lubricate bearings & gears as well as ways.
I like this solution as it means that I can use one drum of oil for all my machine lubrication. Worth considering if you are only doing hobby type things and don't want to have 3 or 4 drums of oil sitting around.

Michael

I found this rather lengthy explanation as I stumbled around the 'net. Apparently it was posted here in PM some time ago .......


33. What kind of oil should I use on my lathe/mill?

This is certainly a frequently asked question! The first answer is to
use whatever the manufacturer's manual suggests, presuming you have
a manual for your machine.

Feed-screw threads, half nuts, back gears and similar are usually
lubricated with a heavy oil such as Vactra 2 or 3, or grease if
protected from chips and swarf. Some suggest a mixture of oil and
STP oil treatment. (South Bend recommends the same oil as used on
the ways).

Beds and "ways" are often treated with special oils, called "way oils".
ISO 68 (medium weight). Examples: Exxon Febis K 68, Shell Tona T-68,
Sun way lube 1180, Mobil Vactra No 2, Texaco Way lube 68, Gulf Gulfway
68, Chevron Vistac 68X.

Spindle bearings call for "spindle oil" such as Exxon Nutto H32,
Shell Tellus V32, BP HLP32, Castrol Hyspin AWS32, and Mobil DTE 32
(in this case the 32 is the ISO VG32 spec, about the same as SAE
10-weight, and is what Myford recommends for their lathes). ISO
grade 22 is also used (it's what South Bend recommends, for example).

All three types are available from the better supply outfits,
such as MSC. Remember that the money you spend on proper oils will
be a lot less than the cost of replacing the machine!

That's a lot of names, but how do you choose? Probably the first
thing to do is follow the manufacturer's recommendations, if you
can find them.

South Bend, for example, recommends four different lubricants for
their 9" and 10" lathes: CE1671 bed way lube, CE1603 medium machine
oil, CE-1600 light machine oil, and CE1625 teflon grease. These are
available from South Bend, and the discussion and tables below
should allow you to choose an equivalent oil available from an
industrial supply house.

Failing a manufacturer's recommendation, a key issue is typically
the viscosity. There are a number of ways of describing viscosity,
most of them confusing. We will now make a quick attempt to remove
some of this confusion.

Machinery's Handbook has a nice section that goes into the different
kinds of oil performance for lubrication and how viscosity changes
with temperature. But it's not really detailed enough to make
a practical choice.

Most people are familiar with the SAE viscosity scale, because most
people have bought oil for their cars. What isn't immediately apparent
is that there are two SAE scales, both in common use: one for crankcase
oils, and one for gear oils! There is an ISO scale (VG numbers) and there
is the Saybolt scale. Let's start with the Saybolt scale, which is
measured with something called the "Saybolt Universal Viscometer":

In said viscometer, the oil flows through a tube 0.1765 cm in
diameter, 1.225 cm long, under an average head of 7.36 cm, from
a vessel 2.975 cm diameter. The time in seconds required for 60 cc of
oil to flow through the tube is the viscosity in seconds Saybolt.
The specification is typically given at a particular temperature,
such as 100 degF or 210 degF. (Something tells me that the numbers
in the description above were originally English units, not metric.)

With that description of Saybolt Universal Seconds (SUS) in mind,
let's look at the SAE scales. First, for the crankcase scale:

SAE SUS @ 100F SUS @ 210 F
5 92 38.5
10 165 44
20 340 54
30 550 64
40 850 77
50 1200 93

In addition, "Mark's Standard Handbook for Mechanical Engineers",
Eighth Edition, lists the following for Crankcase Oils:

SAE SUS @ 210 F
20 45 min - 58 max
30 58 min - 70 max
40 70 min - 85 max
50 85 min - 110 max

But it goes on to show the following for gear and transmission oils:

SAE SUS at 210 F
75 40 min
90 49 min
85 63 min
90 74 min - 120 max
140 120 min - 200 max
350 200 min

So you can see that the viscosity at 210 F for SAE 80W gear oil is
about the same as SAE 20W crankcase oil.

Finally, there's the ISO VG scale. From perusing a number of Mobil
oil data sheets, it appears that the ISO VG value of an oil is
exactly its viscosity in centiStokes at 40 degC. Unfortunately,
the relationship between cSt at 40 deg C and SUS at 100 degF is
not a linear one. But you can find a fairly complete table
of tradeoffs at http://www.bconnex.net/~noco/nocovisc.htm.
Here's an abbreviated version that relates cSt and SUS @ 100 degF:

cSt SUS at 100 degrees F

10 58.91
15 77.39
20 97.77
25 119.3
30 141.3
35 163.7
40 186.3
45 209.1
50 232.1
55 255.2
60 278.3
65 301.4
70 324.4
75 347.6
80 370.8
85 393.9
90 417.1
95 440.3
100 463.5

(Taken from ASTM Table 1, D2161-63T)

Also, SUS at any temperature is SUS at 100F multiplied by
1 + (t-100)0.000064

ie 58.91 SUS at 100F is 58.91x(1.007)= 59.32 at 212 F

To pull this all together, let's look at some specific examples.
Above, we mentioned the South Bend recommended oils. Not only does
SBL give part numbers, but they give viscosities in SUS at 100 degF:

Usage SBL p/n SUS @ 100 F ISO VG SAE (crankcase)
light spindle CE1600 100 21 5
medium machine CE1602 150-240 30-55 10-20
way lube CE1603 250-500 57-100 20-30

Thus, a good substitute for SBL CE1600 would be Mobil Velocite No. 10,
which is an ISO VG 22 spindle oil. Mobil Vactra No. 2, ISO VG 68, is
probably a good substitute for SBL CE1603 - it matches the viscosity
and is formulated as a way lube (has appropriate coolant separability
and corrosion resistance).

Now, multigrade motor lubricants are not recommended as machine oils.
This is for two reasons: 1. Motor oils have additive packages that are
designed to avoid corrosion and condensation problems that are unique
to the heat cycle and high-temp operation of an engine, problems
that are not found in machine tools. 2. Modern motor oils have detergents
that keep the contaminants in suspension (so they can be removed by
the oil filter) - most machine tools do not have a filter system,
so the contaminants will be circulated around to the bearing surfaces
rather than falling out of suspension to the bottom of the gear case.

That being said, there are several people on the list who are
very happy using Mobil 1 motor oil as spindle and countershaft
lubricants. The 5W-30 oil is approximately the right viscosity for
spindle bearings, and the 15W-50 is heavy enough for countershafts
and gearboxes. (Remember that Mobil 1 is a detergent oil, and it has
been recommended that it should be changed a couple of times a year
to flush suspended particles). The final choice is up to you, of
course. Machine oils have their own special additive packages geared
towards the requirements of machining.

Now that you've made a decision about what oil to use, how do
you oil it? Most lubrication charts assume production use,
and give oiling intervals accordingly. I prefer to spend five
minutes oiling the machine every time I use it, just to make sure
everything is wet and topped off.

A suggestion I've read is to oil lathe ways before using, to clean off
dust/grunge that may have accumulated since you last used it. After
work is finished, wipe off but leave a film for rust prevention.

Elsewhere we mentioned the book "A Brief treatise on Oiling Machine
Tools" (Guy Lautard) but nobody's posted a review yet.

After all that, I can see there are good reasons for not using motor oil, especially the detergent stuff. But gear oil is a totally different animal, and no one seems to go into much depth as to why it shouldn't be used. I don't think it is a detergent oil (correct me if I'm wrong), and I don't think it's especially prone to collecting moisture. Most people leave it in transmissions and differentials for decades with no ill effects, and ISO 68 seems comparable to SAE 80W. What am I missing here?

borne2fly said:

After all that, I can see there are good reasons for not using motor oil, especially the detergent stuff. But gear oil is a totally different animal, and no one seems to go into much depth as to why it shouldn't be used. I don't think it is a detergent oil (correct me if I'm wrong), and I don't think it's especially prone to collecting moisture. Most people leave it in transmissions and differentials for decades with no ill effects, and ISO 68 seems comparable to SAE 80W. What am I missing here?

Click to expand...

Perhaps "tackifier" might be the operative word here. There can also be "purer" versions of any given weight of oil ie: cleaner oil or more refined but same weight or viscosity. While gear oil may be of the same viscosity, it is definitely more "sticky". I am only speculating here, I am by no means an expert,.... just another backyard mechanic. You'll note the smell of gear oil too, another clue that it is not the same animal as circulating oil.

Maybe that is a good way to think of it...circulating oil versus gear oil or an oil that stands up to shock/hammer loads better. Then you get into cutting oils.....yeeesh.

Probably not much help,

Jim

Welll............

I need to throw my two bits in here, mostly because I think it solved a mystery....


I have one of Enco's finest 13x40 cast iron wonders out in my shop. It's actually been a fairly good lathe and allowed me to make parts for my American machines. About six months ago it began making a muffled "whack whack" sound. I pulled the headstock top and checked all the gears....no problems. It's become pretty obvious that a bearing is starting to go and the machine is only eight years old. Dang cheap Chinese bearings!

Maybe not....I think it's my fault. The first thing I did was to drain the 'fish oil' out when I took delivery and refilled with some good quality 85/90 American gear oil. Big mistake. I should have used a quality machine oil with thin, flowing characteristics as posted here many times by folks like John Oder.....but I "knew everything".

I'm going to drain the headstock and refill with the correct oil. Hopefully the "whack whack" will go away, but I fear the damage is already done. Replacement parts are available, but my own ignorance caused this. In retrospect, it's amazing that it lasted this long.

headstock oil

Once you get the right oil in that headstock,while the cover is still off,turn the chuck with your hand and watch what that oil does.(DO NOT START THE MOTOR)Once you have observed the "oil pumping "activity in slow motion give a thought to what goes on in there when the thing is running.

borne2fly said:

But gear oil is a totally different animal, and no one seems to go into much depth as to why it shouldn't be used. Most people leave it in transmissions and differentials for decades with no ill effects, and ISO 68 seems comparable to SAE 80W. What am I missing here?

Click to expand...

As noted above the class of machinery is entirely different, and so far that is what you seem to be missing. Dedicated oil for machine tools has been produced and extensively used for at least 75 years. Is that fact something you are missing?

I personally used DTE Heavy Medium in a nice Pratt & Whitney Model C headstock for in excess of twenty years. I am glad I did not use gear oil, which may have not been as kind to its three spindle bearings, the front two of which were quoted me at $1500 each. I think you can get your referenced differential and transmission bearings for a very small fraction of the above.

The gearing in such a headstock will not tolerate heavy oils at all. I once put about 20 quarts of 40 wt (I was more ignorant in 1977) in a 20" Model B P&W - their first gear head with fully ground gear tooth profiles. It got too hot to lay your hand on top, so gave a quick education.

Plain bearing gear head lathes commonly use the head stock lube for the spindle bearings (for certain the thousands of Lodge & Shipley Selective Heads) - which need a thin oil to do any good at all in these super close fitted bearings.


John Oder

1. Many, if not most, of the major oil companies' "way oil" technical data sheets -- including Shell's data sheets for their Tonna oils, Exxon/Mobil's data sheets for their Vactra oils, and Chevron-Texaco's data sheets for their Vistac oils -- note that those products are generally appropriate for moderately loaded enclosed gears, plain bearings, and rolling-element bearings.

2. The "gear oils" traditionally used in automotive stick-shift transmissions and rear ends often contain Extreme Pressure (EP) additives based on chlorine, sulfur, and/or phosphorus compounds that will chemically attack copper and copper alloys, including brass and bronze. Using such an oil in a gearbox containing copper-alloy parts will, over time, absolutely destroy those parts.

Combining that fact with the fact that the material properties of copper-bearing alloys make them well suited to internal use in gearboxes -- bushings, sliding bearings, and worm wheels are commonly made of bronze -- provides the foundation for the general prohibition on using "gear oil" in gearboxes.

John

I believe that operating temp. plays a big roll as well. I know that the transmission on '72 one ton gets well over 100 degrees on the coldest days same for the front and rear diffs. On the other hand if my gear head gets close to 100 degrees there is a huge problem. That should translate to the different viscosity. If you notice the 80 weight is at sus is at 210 degrees while the iso 68 is at 100 degrees. Oils act differently a different temps. I bet if you did a quick unscientific test, say take 2 paper cups, put the same amount of oil in each, poke equal sized holes in them an time them at room temp. I think the iso 68 would empty faster. Chances are you head stock take a good long while to get 25-30 degrees over room temp. let alone to get to the temp where 80 weight will flow at the same rate.
Terry

Borne, be sure an read #2 in the post by John Garner, among the many good posts above that is a very important reason not to use gear oil where it does not belong.
James

Headstock Oil

Hello: I use Shell Omala 100 in the headstock of my 1940 LeBlond.. Omala is an industrial gear oil not the same as hypoid ep oils.. Mike

John Garner said:

1. Many, if not most, of the major oil companies' "way oil" technical data sheets -- including Shell's data sheets for their Tonna oils, Exxon/Mobil's data sheets for their Vactra oils, and Chevron-Texaco's data sheets for their Vistac oils -- note that those products are generally appropriate for moderately loaded enclosed gears, plain bearings, and rolling-element bearings.

2. The "gear oils" traditionally used in automotive stick-shift transmissions and rear ends often contain Extreme Pressure (EP) additives based on chlorine, sulfur, and/or phosphorus compounds that will chemically attack copper and copper alloys, including brass and bronze. Using such an oil in a gearbox containing copper-alloy parts will, over time, absolutely destroy those parts.

Combining that fact with the fact that the material properties of copper-bearing alloys make them well suited to internal use in gearboxes -- bushings, sliding bearings, and worm wheels are commonly made of bronze -- provides the foundation for the general prohibition on using "gear oil" in gearboxes.

John

Click to expand...

I'm curious. If the lube in a manual tranny has compounds which attack bronze or brass alloys, how did the synch rings in the Muncies or T-10s or Top Loaders or NVs hold up? Not disputing your statement, just puzzled.