I have a four speed gearbox and the thing just keeps leaking gearbox oil. The leak is a slow leak, but it tends to be annoying when I park the car in friends driveways. The oil is leaking from the back of the gearbox where the drive shaft is going into the gearbox. The oil leak has even caused the oil level in the box to go really low, but at that point it stopped leaking. I changed the gearbox seal and refilled it with oil and now the leak has started again. Can anyone help me with this problem. Thanks.