This is not an answer to your specific question as I only have the MKl D/W, but that was supplied to me by Model Engineering Services with a small canister of extremely thick grease. I've used this religiously over the last 40 years and it works well and to a degree reduces the very loud noises that this type of gearbox produces. I'm not aware of the MKll gearbox design but I would have thought that any grade of oil would want to flow downwards I.e. away from the parts that you are trying to lubricate.

Phil

In the absence of more specific information a a good general rule for any sort of machine tool that folk like us are likely to own is :-

Light machine oil = ISO 32 hydraulic oil with anti wear additives. Use for spindles, bearings, wick feeds, sealed aprons and sealed gearboxes et al. Many pump fed way lubrication systems need this oil rather than the ISO 68 too. (My Smart & Brown 1024 uses quite a lot over a year.)

Heavy machine oil = ISO 68 dual rated way and bearing oil. Use for bedways, feed screws, open gearboxes, open aprons, back gear, drop gear train et al. Also great for household "Honey Doo" jobs like hinges were you wan't it to hang around for ages.

I've been using Castrol Hyspin AWS 32 and Magna BD 68 for pushing 40 years on such duties as advised by the technical applications department.

Don't use single rated heavy duty way oil on our smaller machines. Its too sticky and destroys the feel.

Clive