I have a Tjet , was under the car today and noticed oil built up around both seals of the gearbox, what I have known for a while is that when the car is cold and I change down, sometimes it will have a quick whine , I will attach pictures,
mine has a slight leak from the seam between the two halves of the gearbox, over time it started to whine which was cured by topping up the gearbox oil.
My local dealer quoted £500 to reseal the box (its a liquid gasket) so im sticking with the top ups for the time being