just to add,

I use the sticky chain saw chain oil on exposed back gears, 5-40w Synthetic D engine oil on everything else except enclosed gearbox's which get Dexron 3 or 4 Auto (red) gearbox oil……….

also when my last bit of Q8 suds oil gets used up will prob go for Hydraulic oil for coolant………

now what da ya think of that………?????????……….hahaha……..

ps. all the oiling points on my S7 and Col / student are now converted to gravity feed……

the stupid original Myford oil can is in my black museum never to b used again……..

and lastly, al my machines are now covered with old blankets and Duvet's with a low wattage, curly whirley bulb in a work lamp to keep condensation away…….they are on 24/7 till the spring…..roll on spring / summer……

clogs

They will all flow when they warm up regardless. Hence why theres multi oils ie 0W/40W where the 0W flows when cold.

Head stock gears and transmissions Hydraulic 68 or AWS68 translates to what the quality producers recommend.

At one time, automotive gearboxes and rear axles used SAE 90 or the Hypoid derivatives, but with the advent of front wheel drive and no bevel or hypoid gears, the need has gone away. Modern car gearboxes seem to run quite happily of whatever oil is in the engine. Engine oils contain all sorts of additives to prevent oxidation at high temperatures, frothing and viscosity improvers, as well as detergents. None of these are likely to be needed if used in the gearbox of a lathe or milling machine, but probably won't do any damage either.

Hypoid oils can be reactive, containing sulphur compounds which react with the gears, to attach themselves to the running surfaces to reduce friction.

Machine oils are likely to be less sophisticated than engine oils, since the temperatures are lower (I hope that no machine runs with an oil temperature in excess of 100C!), and possibly apart from rubbing pressures on the gears, the pressures will be lower.

So, at a pinch, you would probably get away with using an automotive oil. It may even work out cheaper to buy 5 litres of SAE 10W/30 than a small quantity of something specific! HERESY!!!

Howard

Valid point that Howard couldnt agree more.
The own brand or cheap oils think are around £18 5 ltrs, dearer than Hydraulic oil delivered.

Robin there should be some where a fill level, whether a window or just a marker of some sort.
Current lathe has a window for the oil level, spindle gear picks up the oil and splashes it around. Fairly sure oil level at that is below the bottom of the bearings but it does have a top feed as well same with a 140.