Oil Leak - gearbox ?

[GraeV11]

Hoping you people out there can provide some comfort or some direction; I have a small but persistent oil leak from the rear of the engine. It appears to come from the seam where the gearbox attaches just by the gasket for the sump flange (I did previously think it was the sump pan gasket but having cleaned it up and used the talc powder test find I was wrong). I am praying it is the gasket for the sump flange that is spraying but became paranoid today when I noticed the oil drips are quite clean and the gearbox oil is lower in in the sight window than I remember. I thought that there is no way the gearbox oil can migrate to this seam ?? The bike is running fine and the clutch is as perfect as it can be. I haver run it in this state for over a hundred miles with no adverse affects. Please tell me not worry whilst the gaskets wind my way to to me in the post and I polish my spanners. Thanks.

[The Monkey]

Gearbox oil can and will migrate to that seam via tired seals. Clear oil is likely gear oil (smells different too). Sounds like a slow leak and your clutch hasnt been affected yet so either ride it (keeping an eye on the level) till it does affect clutch performance or get the repair done before good weather riding or long trips. When the job is being done replace all seals/gaskets associated with engine and transmission that can possibly leak into the bell housing.

 

Try changing the transmission oil first. Some gear oils claim to have seal swelling qualities, stick with a proven brand and correct weight. This may delay the inevitable. Cheers

[GraeV11]

Thought that would be the case. Not feeling very lucky at the moment ! Thanks for the advice.

[gstallons]

Find someone with a UV light & appropriate dye and start looking.

[GraeV11]

Find someone with a UV light & appropriate dye and start looking.

 

I am on to it. Great idea.

 

Gave the clutch some, ahem, stress testing this afernoon and no slip could be had. Feeling a bit more optimistic. The people that live in my road hate me.

[polebridge]

Hey. I had a really annoying problem with an oil leak at the rear of the engine/gearbox also. Don't know if yours is the same but mine was the steel braided oil line that runs from the frame down the rear of the engine and feeds into the lower oil sump. What happened is it was making slight contact with a sharp edge on the the left side of the shifter housing. Over time it actually made a small cut into the line. I thought at first that it was coming from the engine or the gearbox. It took me a long time to figure it out. I finally wound up ordering a new line which had to come from Italy. Took a month to get it but it fixed the problem.

 

My bike is a 2004 Coppa Italia for reference. Hope this helps.

[GraeV11]

Hey. I had a really annoying problem with an oil leak at the rear of the engine/gearbox also. Don't know if yours is the same but mine was the steel braided oil line that runs from the frame down the rear of the engine and feeds into the lower oil sump. What happened is it was making slight contact with a sharp edge on the the left side of the shifter housing. Over time it actually made a small cut into the line. I thought at first that it was coming from the engine or the gearbox. It took me a long time to figure it out. I finally wound up ordering a new line which had to come from Italy. Took a month to get it but it fixed the problem.

 

My bike is a 2004 Coppa Italia for reference. Hope this helps.

 

Thanks for that. I have been away on work so will check it out at the weekend.