100k miles, time to check / change gearbox oil ...
Hahaha
Yes, there's the filler / level plug (nearsidetop right just above front brake disk);
Is that the drain plug? Looks like it, starts to unscrew .... mmm, er this drain plug seems rather long ... but oil is coming out.
Hang about. The book said a plug with a square hole ... this is a normal bolt head. STOP!
I had actually been undoing the bolt that holds the reversing gear actuator lever ... if you take it out completely there will be a clunk as it drops inside then it's gearbox change time, not just oil!
The drain plug is hidden among the engine mounting ... OK, I was careless!
Marc, have you some cutaway diagrams of the gearbox you could post? Assume it's the same on most of the manual boxes?
Ciao, Capn K
PS: The drain plug needs an 8mm square allen key (or a suitably ground down 10mm hex one).