Gearbox leak, speedo drive.

[68C]

My 04 Rosso Corsa has a gearbox leak coming up through the speedo drive. It is definitely gearbox oil. The gearbox oil is level in the sight glass with the bike level.

 

I can't see any oil seal, does anyone have any ideas?

[rex007can]

Could a blocked breather valve/hole be causing pressure buildup to push oil up the cable?

[gstallons]

Yes. To find that you could go for a ride and stop the bike. Then remove the fill plug to see if there is pressure built up in the transmission.

[HaydnR]

Could a blocked breather valve/hole be causing pressure buildup to push oil up the cable?

 

 

That's what it was on mine. I removed the breather bolt/cap, pried the crimped cap off and cleaned it out, re-assembled, job done.

[68C]

Is this breather under that black plastic cap just behind the speedo drive, I assume it is also the filler plug?

[HaydnR]

Is this breather under that black plastic cap just behind the speedo drive, I assume it is also the filler plug?

 

no it is right at the back of the box by the clutch cylinder (no.14) a prime location to get full of crud

 

 

[68C]

Many thanks, I'll have a look at that tomorrow morning.

 

 

Rather a belated edit: Took the valve off, cleaned it by popping off the cap and refitted it. Instant success, just need to clean baked on oil from the crossover now. Thanks for the advice.