999 Clutch Push Rod Oil Leak :-(

Discussion in 'Technical Help' started by trig, Apr 10, 2019.

  1. Hi
    I have had a very minor leak from this area (clutch slave side) for a few years on my bike. I have replaced the push rod o rings several times and I can't recall that being successful or there being any damage/wear to the old o rings.
    I have removed the clutch slave and sprocket cover to have a closer look and there is definitely engine oil weeping from the rod hole. It is not coming from the slave, alternator cover sealing or the layshaft seal.
    The rod rotates just by using my fingers so the thrust bearing has not seized but it has always been trapped within the thrust bearing. Therefore the rod has always been dismantled and assembled (greased to help o rings) carefully from the clutch side.

    What causes the rod hole to continue leaking?
    Are there o/size o rings available?
    Has anyone tried machining extra size or even slightly oversize grooves in the rod?
    Is there anything I am missing? I would have thought 2 o rings would be ample to seal.

    Also, there is an o ring in the MPL clutch slave face. It is o/size on the rod. Can anyone confirm that its function is purely to keep muck away from the slave internals?

  2. the clutch push rod is not unique to just the 999 its pretty much over the ducati range.

    On the push rod are two o rings that when in situ, sit either side of an oil gallery inside the engine. This rod is meant to be removed from the slave side but with a bit of push can come out through the clutch side which can damage the oil seal o rings.

    id go with new o rings on the rod and fit it from the slave side...
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  3. Trig, re your message: when you order your belts after subscribing to the forum remind me and I will put two new CCW push rod O-Rings in FOC
    I've PM'd you the link for the forum discount instructions and Belt prices...
    #3 Exige, Apr 10, 2019
    Last edited: Apr 10, 2019
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  4. I had the same oil leak after fitting new seals on a 900 ss engine, what was happening was the seals were getting damaged by a sharp edge on the crankcase as the rod was reinstalled, cured by removing the left hand cover and removing offending sharp edge Drip cured
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  5. There is also an oil seal at the clutch side in front of the needle roller bearing inside the mainshaft.
  6. Thanks for replies. I will remove any sharp edges and try assembly from the left side but I cannot see what difference it will make. I have checked old used leaking o rings. I cant see any damage at x10 magnification.
    Andyb: With the oil gallery, why is there be an o ring for the near side?
    Pauldonjuan: What cover are you referring to?
    Derek: I do not have a leak on the clutch side.
  7. The oil seal is on the clutch side of the main shaft. If it is failing oil will find its way through the shaft to the slave side. Item 30 in this pic from the parts list. Screen Shot 2019-04-11 at 18.00.11.png
  8. Wouldn't failure of this seal show itself by leaking into the clutch? I assumed the rod would be covered in splashed oil where there is a gap in the tunnel that it passes through and that is the reason for having the 2 o rings in that position. Am I wrong?
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  9. Thinking about it, yes. But since one end of the shaft is at the clutch and the other at the slave there should be no oil to get through the shaft unless there is an opening into the centre tube from within the gearbox, which I'm sure there isn't.
  10. I had this on my 916. The clutch side oil seal failed. It was evident from the light oil spead radially from the centre like tendrils. Easy to check, just remove clutch. A further sympton was a well oiled side stand, which i incorrectly assumed was an over oiled drive chain and/or the rod rings. The oil seal is a very simple fix, but you have to remove clutch casing. I cant recall any difficulties. I never even drained the oil, just leant the bike over on its sidestand. Which has the 916 lean.
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  11. I believe there is a needle roller bearing behind the lip seal. It needs oil lubrication from somewhere. There is an opening.
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  12. The push rod is like a prick in a shirt sleeve on my bike but I can feel that the o rings are making slight contact with the bore. However I do wonder if one of the o rings slips out of the bore in use. Also the finish in the bore does not look good. It is difficult to be sure about the finish as I am only checking by light. The width of the o rings currently fitted are narrower than older o rings that I have used in the past.
    #12 trig, Apr 15, 2019 at 1:38 PM
    Last edited: Apr 15, 2019 at 4:26 PM
  13. Ours are the thinner type - never had any complaints of leaking. Not sure why and when they changed spec at Ducati.
  14. I am absolutely sure the o rings you supply are fine as I can definitely feel the contact with the bore.
    i would still like to know the answer to this:
    'Also, there is an o ring in the MPL clutch slave face. It is o/size on the rod. Can anyone confirm that its function is purely to keep muck away from the slave internals?'
    AND why doesn't this seal the offending leak?
    I don't understand the relevance of a leaking lip seal but I will check it anyway.
  15. I developed a leak from there after my chain snapped!
    The end whipped forward and hit the side casing making the rod through hole slightly oval!
    Check your hole is round ;).