Unimog Club UK

Any synthetic gear oil 75/90 in the hubs diff but the gearbox get millers or Morris oils the gearbox needs to be gl 5 spec if you want to be absolutely correct buy from a Mercedes Unimog dealer but you'll pay for it.
Because your not going to overload your machine you could use standard oil and change regularly I like this because you see the condttion and levels at regular intervals always check the levels before you drain to see if you have any seals gone.
Moose