300TDI: 15W/40 This grade can be found as part synthetic or mineral.
R380: MTF94 This oil is fully synthetic
Transfer and axles: API GL5 of: EP90, EP80W/90 or EP75W/90
GL4 is the recommendation for the older vehicle, and of the the three oils are SAE 90 so the same other modified to be a multi grade, therefore will become similar to a SAE 75 or 80 in a specific ambient temperature band.
Loads of infotech subject of oils on the www if your still unclear. Plus sites like Comma, that will give u the exact specifications and terminology, of the above.
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