As it says really.
Car is a 1989 CTi 1.6, with BE3 gearbox.
Don't want to be bothered with draining the oil if it can be avoided. Need of course to jack the car up to change the shaft (if it matters, the N/S, but I will probably be changing the O/S one sooner rather than later), so it struck me that if the car is jacked so high, the oil will be below the level of the driveshaft orifice.
I know the gearbox oil level is correct so possibility of it having been overfilled isn't a concern.