[rondeo]

Thanks for a truly gearbox warming story!

Clutch engagement seems a likely suspect in fluid blackening. Wear products in the fluid reduce its lubricating quality and form deposits.

Given the expense of fluid changes, maybe some oil quality guide would be handy. Age degredation maybe explains maximum 3 years between changes specification. Removing the filler plug on top of the transmission and poking a bamboo skewer or suchlike might help in deciding to change or not before the 60000km specified interval.

City driving and many clutch engagements vs highway driving might mean it's likely not always necessary to change fluid early. With mainly highway driving the fluid looks pretty clean in mine.

When you think about it, the fluid is doing two seeming contradictory jobs: allowing the clutch plates to engage without slipping, while at the same time lubricating the gears. No wonder it stinks like it does.