SMD Oils

[Pavel]

In a number of posts regarding valve clearances, late last year, the subject of oil types for SMDs was raised - with interesting posts from both Brian and BarryM.
Brian made the point that the series 3 Castrol MP oils had an anti-squark additive that was detrimental to cylinder bores - unless used frequently for heavy work. My SMD is only rarely used for heavy work - the best being medium duty.
As well, Castrol Agri MP Plus that I use [for the last 4 years] here in Oz is a 20/40.
However, the tractor starts, runs and pulls well, especially since I refaced the head, valves and seats, plus had the injectors cleaned and re-calibrated 4 years ago.
My query:
BarryM uses the word WAS in designating the Mobil, Castrol and Shell oils used in the past and, as far as I'm aware, none of these were formulated for use in transmissions.
So, is there an alternative to Agri Plus MP 20/40 which is also able to be used in the gearbox and rear axle?
Pavel

[Brian]

The tractors were "formulated" to use the engine oils in their transmissions and hydraulics.

Just a small point, HDD 30 (Series 3) is OK in the engine provided you clean the filters and drain the oil after a few hours when you first start using it. It is a heavier detergent oil than HD but it does not have the brake additives. It is just a "straight" oil and will really clean up your engine.

It is the "Multi Purpose" or "MP" oils that contain the anti-squark additives for the brakes.

Shell Rotella or any lorry engine oil similar would also be good in both engine, transmission and hydraulics.

Barry is the oil guru, he is ex-Mobil!