was claning up my wheels and re-greasing the brkae pads to stop them squealing when i noticed this. any ideas? i'm thinkin the oil filler bolt on the gearbox. i think thats where its located, near the dark patch on the cable sprayed it with loads or degreaser and washed it so its cleaner so will be able to have a beta idea with traces of new oil apperaing. And just to make the day, its now raining on all my cleaning efforts.