clutch gasket blows all the time

[jihem]

I have a wonderful bike (2002 blue GB STW 1100), it starts to be really dialed up nicely suspension wise, the PC III does a correct job at controlling a pretty hefty delivery (about 93 CV at the back wheel with the KS Scola cam), the bike is really fast, but it's the third clutch gasket I'm going thru (including two time new clutch disks)...The bike has only 50.000 kms.

 

So it starts dripping oil at the back of the engine and diagnostic is always the same: clutch gasket gone, clutch starts to slip more and more...

 

Is there a reason why I would always end up having the same trouble ? Seems to me it happens when I really start riding the bike strong altho I never pass 8000 rpms.

What can I do to stop having that expensive and time consuming problem (speak slowly, I'm not a technician at all...)

[docc]

Is this the rear main seal of the engine or the front gearbox seal?

[jihem]

rear from what I know.

(warning: i don't know if it's relevant, but while the engine comes from a V11, the gearbox is the 5speed 1100 sport one)

[raz]

Let's rephrase it to avoid confusion: does it leak gearbox oil (smells awful) or engine oil (smells, uh... engine?)

[jihem]

engine smell...

[luhbo]

... altho I never pass 8000 rpms....

 

Next time check what sealing ring you've been sold.

Chance 1: wrong material (8000 min-1 at such a large diameter results in remarkable circumferential speeds)

Chance 2: wrong orientation of the ring (there should be an arrow or the like on it indicating the turning sense of the crankshaft)

Chance 3: mounted without using the proper tools (no hammer for such a big ring)

 

The last and possibly most expensive thing would be that the rings have already made a small groove into the end of the crankshaft. Try to position the next ring at a slightly different position (further in/out).

 

Hubert

[jihem]

Well, I don't do the repairs myself, it's done by a garage specialised in Guzzi (they have been doing it for more than 15 years) so I reckon they have the right tooling, and put the right parts in.

 

 

Well, as it is, it's a rather expensive repair as they need to open up the engine...takes more than ten hours, or so i've been told...

Your last point is interesting: i will forward it to the guys handling the repairs.

[Baldini]

...the rings have already made a small groove into the end of the crankshaft. Try to position the next ring at a slightly different position (further in/out).

 

Hubert

 

I had this on a T3 crank once. Crank was marked around where seal lip sat, corrosion or wear can't remember, bike was new to me, maybe it had been standing. I cleaned it up best I could & mounted seal so lip was on different part of crank - worked OK. Do you know age/history of motor?

It isn't oil contamination from breather return?

 

KB

[luhbo]

...it's a rather expensive repair as they need to open up the engine...takes more than ten hours, or so i've been told...

 

Not at all! Just pull the gearbox and the clutch and you are there. Don't give too much on this shop (which should be able to keep your Guzzi onroad btw).

Another thing is that it's rather unlikely for the oil to get into the clutch. It comes from outside the clutch and normaly gets thrown away by the rotating wheel. Then, if you believe that sipping oil would enter the clutch it could as well be a sipping camshaft cover. Already checked?

 

Hubert

[jihem]

i guess I have to change Guzzi shop (not an easy task around here i tell you) to get to the bottom of this story.

[luhbo]

Who knows. A shop normaly gets from Mandello a certain guideline how much time a certain job should take.The question is whether they're working exactly after these guidelines and the next question is what they will take from you for this.

If you trust in this shop and as long as they're normaly running their business to your satisfaction I would probably not go to another one. Maybe those might fix the leaking seal better and instead forget the oil filter next time.

 

Hubert

[Baldini]

Who knows. A shop normaly gets from Mandello a certain guideline how much time a certain job should take.The question is whether they're working exactly after these guidelines and the next question is what they will take from you for this.

If you trust in this shop and as long as they're normaly running their business to your satisfaction I would probably not go to another one. Maybe those might fix the leaking seal better and instead forget the oil filter next time.

 

Hubert

 

I dunno, regardless of hours quoted, it's not rocket science. Third time same problem, same shop? You'd've hoped a competent Guzzi shop would've caught this after two attempts - or was earlier work done elsewhere? It can only be oil from:

 

1.Crankshaft seal

2.Clutch hub/gearbox input shaft seal

3.Camshaft end cap

4.Crankcase breather/return (seals inside bellhousing or seeping down into bell housing from damaged external pipe).

5.Crankshaft bearing carrier gasket

 

Unless I forgot something there's nothing else???

 

Can gearbox oil get into clutch pushrod tunnel - I can't remember?

 

Discs were replaced cos of oil comtamination not wear?

 

Which clutch you using?

 

 

KB

[raz]

Can gearbox oil get into clutch pushrod tunnel - I can't remember?

Yes, and I think it will end up right on the plates, let's call it #6. Actually there is also a #7, the two lower bolts for the crankshaft bearing carrier. They are drilled through and should be taped with PTFE.

[jihem]

Well, the shop is taking the bike back on saturday and we'll get to the bottom of this. I can't answer most of the questions right now but will get them to the mechanics and hopefully that can start a fruiful END OF THE PROBLEM.

 

(funny, was just watching Dr House season finale and it came to me that this technical topic section is very much like Gregory's diagnostic team. Who's 13 ? )

[motoguzznix]

1.Crankshaft seal

2.Clutch hub/gearbox input shaft seal

3.Camshaft end cap

4.Crankcase breather/return (seals inside bellhousing or seeping down into bell housing from damaged external pipe).

5.Crankshaft bearing carrier gasket

Jihem

 

This is a good summary of the problems that may occur.

But only issue 2. makes the clutch slip. There are the following opportunitys that make gearbox oil enter the clutch:

 

1. There is the seal ring in the clutch housing

2. There are two conical shaped rubber seals at the rear of the clutch pushrod - access from the rear of the gearbox.

3. If the hub is not tightened correctly, oil can enter by the Orings underneath.

 

Either of them can lead to clutch failure.

 

When engine oil enters the clutch housing it normally finds its way to the bottom hole outside the clutch.

 

Good luck for your repair