I will dig a fossil out a bit (I'm just looking for information about the oil in the gearbox and coolant), but when I read "that the service does not provide for oil change in the gearbox" it is black blood flooding me. Of course, it must be replaced in all types of gearboxes. Not only in the machine, but also in the manual. In old cars, it is said how much to change oil. In new ones they don't give it anymore. The manufacturer does not assume oil change in the box, because it assumes that after 10 years we will buy a new car, or we will do a costly repair at an ASO.