I've got a gearbox oil leak aswell. It's definately coming out of the selector shaft and only appears to be minor, i think?
I've only had my 172 for 5 months and I took it for its first service/MOT recently. My local garage mentioned I had a 'serious' leak from the selector shaft and that it needed fixing by a gearbox specialist, probably at a cost of £500+ . They however said that the gearbox oil level only needed slightly topping up, which they did. They also offered to have a look at the oil level 2 months later free of charge to see at what rate it is leaking. To my suprise, they said it need 2 litres of oil at a charge of £16+VAT, that's 2 litres lost over just 2 months! In comparison 2 months earlier at the service it needed only a 'top up' after over 1 year of leaking! I think they've diddled me. I curious to hear what people think. Everyone talks about minor selector shaft leaks which you need not worry about. No one has mentioned a major selector shaft leak, especially 2 litres over 2 months! I certainly don't want to spend £500 quid on gear box repair!