What oil to use on a Grayson lathe

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

T

Even the EP gear oils don’t say “don’t use with yellow metals” on the user instructions. You are supposed to use the correct specification without needing to know the details. e.g. https://www.halfords.com/motoring/engine-oils-and-fluids/gearbox-oil/comma-gear-oil-ep80%2F90-gl4-1l-124341.html

T

Thats because modern gear oils are mostly yellow metal compatible. It was only GL5 that wasn’t, not the GL4 in your picture and not GL3 etc.  And modern GL5 is now mostly compatible too.

[alecs]

On alecs Said:

On Robert Atkinson 2 Said:

T

Even the EP gear oils don’t say “don’t use with yellow metals” on the user instructions. You are supposed to use the correct specification without needing to know the details. e.g. https://www.halfords.com/motoring/engine-oils-and-fluids/gearbox-oil/comma-gear-oil-ep80%2F90-gl4-1l-124341.html

T

Thats because modern gear oils are mostly yellow metal compatible. It was only GL5 that wasn’t, not the GL4 in your picture and not GL3 etc.  And modern GL5 is now mostly compatible too.

No warning on here either:
https://www.halfords.com/motoring/engine-oils-and-fluids/gearbox-oil/comma-sx75w90-gear-oil-gl5-1l-124366.html

You are re-enforcing my point really, you have to consider the detailed specification not just the headline type and viscosity.

Even among ISO-32 hydraulic oils there are variations that are specifically low corrosion for copper. On the otherside of the coin, when some countries reduced the amount of sulphur in their jet fuel they started having problems with fuel pumps seizing. This was particuarly a problem with Sovient designed engines. There is no minimum requirement for suphur in Jet A fuel. The US military had similar problems with HUMVEE diesel engines when they started to run them on Jet fuel (saves logisitcs to have a common battlefield fuel for aircraft and ground vehicles). Some, but not all, fuel pumps siezed. Different makes, all built to the same specification were affected. Traced to specific batches it was found to be due to different, within specification, steel alloys used for parts. Possibly the parts were from subcontractors. A change to the fuel pump specification to run on low lubricity fuels sorted it.

Back to the original point, I find it highly unlikey that the Grayson headstock berings were designed to use a ISO 220 gear oil. If bearings arn’s worn it’s possible that the spindle is not assembled correctly possibly missing a thrust washer that also acts as as a oil seal or similar.

Robert.

[alecsParticipant @alecs]

I should think Grayson bearings are much like Myfords, Drummond’s and most others of that era, no thought given at all to sealing the bearings. Oil dripped in the top and cheerfully dribbled out each end of the bearing, ensuring a constant flow of fresh oil. The world was a messier place back then! Men wore dustcoats to keep the oil off their collar and tie, and learned early not to stand in line with the chuck. A black oil slick up the wall behind the chuck was standard.

One thing to look for o n GL5 gear oil is if it says its suitable for synchromesh manual gearboxes, then it is yellow metal compatible, synchro rings being bronze. I think that is most GL5s these days.

[duncan webster 1Participant @duncanwebster1]

Using thick oil will cause increased drag and heat. Whether this matters is down to circumstance. I think messrs Myford et al knew what they were about when they called for 32 grade

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