Oberon Clutch slave leaking

[Darren69]

Gazza, if you do this mod let us know how it works out. I'm thinking my early FR slave failure may alo be due to spinning issues at the slave end.

[Dukedesmo]

Originally Posted by Darren69

Is that the STM Evolutione one?

No it was a US company called Evoluzione Cyclesports. It was a small company and I understand it ceased trading when the owner got divorced? - there's a bit of a story somewhere, Woman scorned and all that.

That said it's a quality piece and they were making them long before many of the other offerings.

[Dukedesmo]

Originally Posted by Mr Gazza

It just remains to be proven whether or not the later pinned rod would be a straight swap for my early one. I am assuming that I would need an anti rotation insert (#22) which I am also assuming would fit straight into my Oberon cylinder.

It stands to reason that I would omit the spacer if fitting a later rod.

I'm fairly certain the Oberon slave on my Monster has the anti-rotation part as standard?

It doesn't get in the way on a standard pushrod so presumably they're all like that?

Also seem to remember I needed the (supplied) spacer on mine which is obviously one of the older rods.

[utopia]

Yes, seconded on that.
I fitted an MPL slave, which I believe is the same as the Factory Racing one, about 3yrs ago.
I pondered the pushrod spin/pin issue briefly at the time but was in a bit of a hurry so I built it up with the old, non-pinned rod (and spacer) for the time being.
As usual, that meant that it drifted from my thoughts and was left like that.
I've had no obvious issues (haven't particularly noticed much blackening of the fluid, but can't say I've looked that closely).
I am therefore interested to know the outcome of your investigations into swapping to the pinned pushrod.

Then again .....
From memory, and a glance at the pics, it looks like the piston in the aftermarket slave has a tab which prevents it rotating.
So any relative movement should be between the pushrod and the piston .. ie outside of the hydraulic fluid system and therefore not able to influence its degrading/blackening.
Or am I missing something.
I could be .. I've not studied the assembly closely.

Had an interesting but inconclusive discussion with Capo regarding the existence (or otherwise) and location of any oil feed tappings etc into the pushrod bearings.
Its something that I intend to look at more closely at some stage but I would be interested if anyone has any knowledge thereabouts.

[Luddite]

Originally Posted by Darren69

Thanks Luddite for clarifying. I guess I need something like a standard 1098 pushrod and slave then for that to work?

Strangely enough, Darren, there's no anti-rotation pin on the 1098. It doesn't appear on the sportsbikes until the 1199 Panigale. Those part numbers for the rod, cylinder and anti-rotation insert are all different from the ones for my Evo so some further research would be needed before deciding which combination, if any, would fit your S4.

Originally Posted by Mr Gazza

I am assuming that I would need an anti rotation insert (#22) which I am also assuming would fit straight into my Oberon cylinder.

As Dukedesmo says, the Oberon cylinder has the anti-rotation slot machines into it; it is only the Ducati version that has a separate insert.

[Dukedesmo]

Originally Posted by utopia

Had an interesting but inconclusive discussion with Capo regarding the existence (or otherwise) and location of any oil feed tappings etc into the pushrod bearings.
Its something that I intend to look at more closely at some stage but I would be interested if anyone has any knowledge thereabouts.

If you look at this pic of my Monster engine whilst apart, you can see that above/around the pushrod hole are a couple of holes in the casting that allows oil to 'splash' into the pushrod channel.



It simply gets splashed up there by the flywheel and allows for the pushrod to be running in oil.

The oil then runs along the pushrod to lubricate the small bearing in the clutch end of the output shaft.

If the oil seal after the bearing fails then oil will leak, albeit slowly, into the clutch on dry clutch bikes - I had this on my 916 and a small amount of oil would leak into the clutch, enough to drip onto the exhaust whilst stopped and then create a smoke screen on startup.

Whilst this is only a problem on dry clutch bikes I would think the left side case is similar and has the oil 'hole' for the pushrod.

BTW when I said the Evo slave doesn't taint the clutch fluid, I don't think it's anything to do with rotation of the pushrod as I'm pretty certain neither of my bikes have ever had the rod rotate - should only happen if the pressure plate bearing seizes and I'm fairly certain if it happened it would soon chew up the 'O' rings on the pushrod that stops oil leaking out of the slave cylinder end.

I think it's something to do with the seals or materials of the slave

[Capo]

The purpose of these holes (later its only 1) is to supply lubricant to the layshaft bearing, there is no way it can get into the centre of the layshaft which is open to atmostphere.

The hole that scoops oil into the layshaft bearing


The other side of the case showing the hole at the top of the layshaft bearing

[Mr Gazza]

Naturally I will report back whether this pushrod mod will work or not.

In order to simplify the question to Luke or Craig, does anyone know offhand what the length of the Oberon spacer piece is? From memory it's about 10/12mm long.
Critically the 696 rod needs to be a spacer's length longer than a standard M900 rod.

It's not a massive ordeal to pop my rod and spacer out I suppose.... but y'know?..

Re the insert. I think that the slot shown on the Oberon drawing looks rather wide for the tiny pin, which I imagine would need to be fairly closely restrained to prevent racking in the slot?.
I will also ask if the insert gets transferred over to the Oberon cylinder on the later models, though I can't remember any reference to it in the fitting instructions.

[Dukedesmo]

Does the layshaft bearing allow oil to pass by?

Because there is definitely an oil supply to the pushrod.

When I have removed the rod there is always a film of oil on there and when the seal at the clutch end failed (actually it didn't fail, I replaced during a clutch service because I thought it was a bit tired looking but I inadvertently fitted the new one the wrong way round and oil pushed through) on my 916 it leaked oil into the clutch - enough to dribble out when parked and create a huge smokescreen from the exhaust when started plus enough to make the clutch slip whilst riding.

Also I doubt those little bearings inside the shaft would last long without oil.

Maybe wet clutch bikes allow oil to get in from the clutch? (no seal?) but the dry clutch bikes need to get oil in there somehow?

[Luddite]

Originally Posted by Mr Gazza

In order to simplify the question to Luke or Craig, does anyone know offhand what the length of the Oberon spacer piece is? From memory it's about 10/12mm long.

Re the insert. I think that the slot shown on the Oberon drawing looks rather wide for the tiny pin, which I imagine would need to be fairly closely restrained to prevent racking in the slot?.

That's frustrating! I've just been out in the (unlit) shed with a torch and found the boxes for every bit I've added to the Evo except the Oberon clutch. I'll have another look tomorrow in the daylight.

As far as the anti-rotation slot is concerned, my pushrod pin hasn't caused any problems over the past six years. And certainly, on my Oberon slave at least, there is no space to fit the original Ducati insert.

[Capo]

A cross section. Note there is no seal after the layshaft bearing, the end of this shaft is open to atmosphere.

[Dukedesmo]

Is the (slave cyl) end of the shaft not within the casting where the oil holes are but ends before the void that the holes feed? Enabling some of the oil to drop onto the pushrod which at that point is a reduced thickness to allow some oil to run along to the other side.

I thought it was but don't have an engine apart at the moment to check.

The 2 'O' rings on the slave end of the pushrod (thicker portion) then are in the outer part of the casting to stop oil from leaking back from there to the slave.

[Mr Gazza]

Originally Posted by Luddite

That's frustrating! I've just been out in the (unlit) shed with a torch and found the boxes for every bit I've added to the Evo except the Oberon clutch. I'll have another look tomorrow in the daylight.

As far as the anti-rotation slot is concerned, my pushrod pin hasn't caused any problems over the past six years. And certainly, on my Oberon slave at least, there is no space to fit the original Ducati insert.

Thanks for your dedication to this Luddite, I've also just suffered some frustration. Just been out and popped the slave off, but completely failed to winkle the pushrod spacer out of the piston, even with a magnet... I know it's in there!!
As expected I couldn't pull the pushrod out from the slave side and gave up at that point, so I still have no measurements. Hopefully those splendid chaps at Winchester can measure from stock.

Thanks for answering the insert question.

[Capo]

Originally Posted by Dukedesmo

Is the (slave cyl) end of the shaft not within the casting where the oil holes are but ends before the void that the holes feed? Enabling some of the oil to drop onto the pushrod which at that point is a reduced thickness to allow some oil to run along to the other side.

I thought it was but don't have an engine apart at the moment to check.

The 2 'O' rings on the slave end of the pushrod (thicker portion) then are in the outer part of the casting to stop oil from leaking back from there to the slave.

The only way for lubricant to get into the centre of the shaft is via the ends. The slave cylinder end is open to atmosphere i.e. not sealed within the engine. If this was the route as you suggest, the lubricant would have to pass the two O rings to reach the needle bearing on the clutch end, furthermore the seal on the clutch end effectively forming a closed vessel making any oil flow almost impossible

[Luddite]

Originally Posted by Mr Gazza

Thanks for your dedication to this Luddite, I've also just suffered some frustration. Just been out and popped the slave off, but completely failed to winkle the pushrod spacer out of the piston, even with a magnet... I know it's in there!!

Have you tried giving it a whack - that's the suggested method from Oberon...



There's an interesting article here on the Avanti website...



http://www.avantiraceparts.co.uk/page.php?id=12

Although it doesn't mention Oberon, it looks like the spacer is likely to be 10mm.