Gearbox /transfer box oil

[FJK]

Can anyone tell me the reason for using ATF in the gearbox and gear oil in the transfer box of early defenders Thanks Frank

[Michael2]

The gearbox has an oil pump built into it, so cold thick fluid won't circulate well.

[rick130]

ATF=Better shifting in cold weather.

The reason we don't use ATF these days is that the oil boffins developed low viscosity manual transmission fluids, gear oils specifically designed for manual gearboxes, oils that don't eat bronze synchros and have the right friction modifiers for better synchro performance and that don't shear in as little as 5,000km as engine oils (the other wide visc fluids used) do when used in a gearbox. (think LT95)