thanks for that, but the hole is so small and I specifically bought a new small funnel for this function, I suspect that the box is on it's way out, but there has been a oil leak at some stage from the front of the engine (probably oil filter) that has "blown back" and coated parts of the engine and gearbox in oil, so was looking to verify that the leak was not coming from the gearbox via the transmission shaft seals for instance and rendering the gearbox low on oil.
One thing under investigation was that the speedo cable screw-on cap appeared to be missing a seal as stated in the Haynes manual, that said I have had this car since May 2004.
What I find difficult to understand is why 5th gear would start to whine (assuming it's starting to wear) and then literally within 2 weeks 3rd develops a whine as well.
But just wondered if there where any other ideas on offer or experience of a similar problem.
Cheers
Jen