as above?

Conventional Oil Dexron3 with 150ml Lubrizol additive. (yes ATF fluid)

Good: Penrite extra light gear oil + lubrizol

Better: Castrol Tranzmax-Z

Best : apparently: Redline Rock crusher.

Theres a allen key Nut on the drivers side, remove it on level ground, stick your finger in (engine OFF) oil should be the same height as the bottom of the hole.

Fill: above.

thanks for the help in both threads mate.

Theres 2 allen keys nuts, one on top, one on the bottom.
Its probably worth undoing the bottom one and draining the box out, then refilling it using the top one.