The 24 mm transmission oil filler and level check plug is on the passenger side (assuming RHD) of the gearbox and is visible and accesible for refil from beneath the bonnet as long as you have long arms and stand on the bumper. (It is easier with the air filter contraption removed) TAKE CARE NOT TO REST ON ThE RADIATOR CAP OR THE NECK SOLDER JOINT MAY BREAK AWAY FROM THE TOP TANK. Refilling is easier from above using one of those gear oil squeezy bottles with extended pipe if you can find one. The Drainage plug is nearer the bottom on the same side and again I believe is a 24 mm. Don't forget the trasfer box oil level again a 24mm plug, if I recall correctly is either on the inboard side with a similar drain plug further down or on the rear. I say if I remember because I've done it so often yet recallig where they are for this evades me as I do it more as habit now. The front and rear diff plugs are aso 24mm. Just watch that top tank neck asso many go by being leant on and are b's to repair. Sorrytobe vagueothe transfer box but onceyouget under there youwil find them by their size.

Good luck

OLDMINIMAN