pirate

Hi, I have a 1996 2.8 auto, the car originally was slow to go into gear and i noticed it had a slight gearbox leak probably from the seal which has hardened gone brittle on the filler pipe. I have removed the gearbox sump complete and drained the oil and now need to fill it up again. there does not appear to be an oil level plug to fill the box up to. How do i know when the box is full. Apart from the oil coming out of the top of the filler pipe.