transfer box

amongst other probs , i think i have a leak from the transfer box on my tdi 300 automatic .
at least thats what i think it is any but i,m a novice so guessing really.
but if it is the T box what can i do , or how can i confirm it .
thanks again

Gearbox oil automatic trans fluid thin (red). Transfer box hipoy 90 .thick (Brown)

is the oil dripping down the transfer gearbox (onto the inspection plate at the bottom)?

it could just be a worn gasket on the inspection plate? you will find that these plates often leak around the bolts.

wipe down the casing thoroughly (with degreaser) until it is spotless. then drive it for a few minutes. any new oil should be checked to see if it is GearOil or ATF. if it is gearbox oil, then drain the transfer box (approx 2.5litres of gear oil SAE80 or 90 will be needed to refill) loosen the plate bolts (approx 2-3mm) and pop a bit of gasket sealant in the threads of the bolts, retighten (leave for a few hours to dry), refill and re-test. that often cures it.

as bonnybagot says, check whether it is ATF (gearbox) or SAE90 (transfer oil) as it may be a leak from the seal between the two boxes (this is more difficult to fix ).