Gearbox, swivel balls, diffs, steering relay - all take 80-90.
I use 140 in my steering boxes. They seem to leak even with new seals...
140 will go a little longer before leaking out. But it's too thick for regular service in the transmission.
Of course any oil is better than no oil. And Land Rovers are famous for getting home with some pretty weird oil running in them, such as bananna oil, peanut oil, etc... It depends on the availability. If you're in the jungle and you need oil, you'll just have to make due.
61 II 109" Pickup (Restomod, 350 small block, TR4050)
66 IIA 88" Station Wagon (sold)
66 IIA 109" Pickup (Restomod, 5MGE, R380)
67 IIA 109" NADA Wagon (sold)
88, 2.5TD 110 RHD non-hicap pickup
-I used to know everything there was to know about Land Rovers; then I joined the RN Bulletin Board.