I only carry the 10l of engine oil on big trips............................have you seen how fast an engine drains with a small hole in an oil filter ? At a pinch you can use the same oil to top up a gearbox or t/case for a short time to get you back to civilisation.
Exactly JK. Even a stone hitting a brake line, any thing like that. To not take fluids when your outback is really not that sensible.
On the same vein. I don't take gear box oil. I am happy to use engine oil for gearbox, transfer case and the diffs to get me to the next stop if that is the only option I have. So I take engine oil and brake fluid. If I have to I'll use brake fluid for the clutch as well, hell, if it's life or death you can use water in the Brake lines (Yea I know, they will be shot after but like I said, life or death). I know what it's like to pack for 6 Months and travel to the remotest places and I just can't see the sense in taking every oil.
The only exception to this if for those in a Patrol and a great LSD, then I wold take LSD oil. As our Paj has a Torson LSD which is gear based I can use the standard oils with no ill effects.
N:B No gear boxes were harmed in the making of the post
I carry ours in a bin on the roof along with the other spares I hope not to need like belts and spare shockies etc.