Colchester (13" / Master 2500) Lathe Lubrication

1. Introduction

All of the specified lubricants are out-of-production (1980s vintage) European Shell products. I've had to translate these into current (2000s) Mobil products.

2. Headstock & Gearbox

The manual recommends "Shell Tellus 37," which is not available in the US. The Clausing Service Center recommended Mobil DTE24 light hydraulic oil, an ISO 32 viscosity grade hydraulic oil, as a replacement for Tellus 37 (I framed my question to them in terms of the Shell oil, not the Colchester lathe, which was probably a mistake).

The lathe itself contradicts its own manual and asks for Tellus 27 on a data plate; this is equally unavailable.

As it happens, taking "27" and "37" as if they were ISO viscosity grades (centistokes at 40deg C., roughly) the Mobil DTE24 at VG 32 splits the difference between the two.

So I've put DTE24 in the headstock and gearbox.

3. Apron and Ways

But see first the discussion of Mobil Vactra and Manual Machine Tools and Way Oils Manufactured Now; the oil I'm using presently (Mobil Vactra) is not in fact an appropriate oil for a manual lathe.

The manual recommends Shell Tonna 68. This is an ISO VG 68 way oil which would correspond to any modern ISO 68 way oil. (But see the Mobil Vactra No. 2.

But the specification called out in the manual for an oil to use if this oil is not available cites an oil with a viscosity (cStokes 40deg C) of 36.2. This happens to be the same number as their citation for Tellus 37; though the other numbers in the specification don't correspond. It could be a typo.

The lathe itself (again) contradicts the manual and carries a plate on the apron which specifies Tonna 33. If 33 were an ISO VG, then 36.2 would probably be within it (just, at the outside of the range).

Further conversation with friends has indicated that a heaver oil such as a VG 68 way oil would have the advantage that it would tend to stay on the ways longer during periods of inactivity. This is a big consideration for me, since the lathe is in a "condensing" environment in the garage and since as a hobbyist my use of it will be occasional rather than continual.

So I'm currently using Mobil Vactra No. 2 (an ISO VG 68 way oil)

4. Rack Grease

The manual says to grease the feed rack weekly, but does not specify the grease to use. I was hesitant about using just any grease in case there might be incompatibilities between the grease and the way oil (sure to drip down).

So I asked Clausing. They suggest not greasing the rack at all, on the theory that the grease just retains swarf.

I'll see how that goes. I may also simply hit it periodically with way oil from the can I typically keep around the lathe.

5. Units for Lubrication

The manual says, for example, that the gearbox requires approximately 2 pints (1.14 liters). But these are British pints, not US pints!

In any event, filling the gearbox with about 1.2 liters brings its oil level up to about the middle of the sight glass; I'm hoping that this is right.

This means as well that the main headstock reservoir takes 2.5 British gallons (11.4 liters), which is 3 US gallons. I'm glad I bought that extra gallon of DTE24. :-)

I'm glad the metric equivalents were there, or I'd have assumed US pints/gallons and ended up a half gallon low in the headstock tank.