Breva clutch slipping

[torino54]

My clutch suddenly started slipping after being parked for many months. What could be possible causes and solutions to look at? Ran perfect before this. Many thanks

 

[londonrob]

Have you checked the obvious, free play in the lever or puddle of oil under the clutch housing?
Is it slipping in all revs or just at higher engine speeds?

 

[torino54]

I've noticed no puddles clutch lever feels normal when pulled in. It engages fine shifts and all then about five minutes into the ride when shifting it just slips engine revs up but the clutch is not engaging. Very strange. Like I said it went into the shop for routine tune up and now this

 

[GrahamNZ]

Check the gearbox oil level. Should be about 10mm below the filler hole with the bike on the centrestand. Too much oil and it can find its way into the clutch housing and contaminate the dry clutch as Pete Roper has posted about.

 

[Penis Rotor]

I've noticed no puddles clutch lever feels normal when pulled in. It engages fine shifts and all then about five minutes into the ride when shifting it just slips engine revs up but the clutch is not engaging. Very strange. Like I said it went into the shop for routine tune up and now this

Look, first of I can't imagine anything that the shop could of done on a routine service that would suddenly promote clutch slip.

What will cause a clutch to slip is either if it is preloaded, which it shouldn't be unless the slave cylinder has seized. Or the plates being affected in some way that means that the clamping force is insufficient to deliver the torque. That could be oiled plates. It could simply be that one of the plates has rusted to either the intermediate plate or the pressure plate and therefore one plate rather than two is beoing asked to handle the torque. It could also be that one of the plates has ripped its centre out. Some early Brevas have had this problem, I haven't heard of other bikes, (Grisos, Norges etc.) which still use the twin plater doing it but it is a Guzzi problem from time to time.

Sorry to say so but the long and the short of it is that you are probably going to have to go in and have a looksee.

Pete

 

[GrahamNZ]

Sound principle - First, fish your feet.

In this case that means checking the simplest possible causes first, like checking that the gearbox hasn't been overfilled and that the level isn't too low. Too high may mean that whoever serviced the bike recently may be liable. Too low may mean failure of the gearbox input shaft seal allowing oil into the clutch area. Oil on friction surfaces which are meant to be dry can cause slippage, squeel, and even grabbiness. Too low can also mean failure of the gearbox shaft output shaft seal, which can be determined by removing the CARC (easy) and seeing if oil is running down inside the swinging arm.

All OK? Then is the clutch making its rattling music when the lever is pulled back and silent when released as it should? If not then the master cylinder or slave cylinder may have a fault. Siezure of one of them could be holding the clutch partly disengaged as Pete outlined.

Only when all else has failed, it's time to bite the bullet and inspect the clutch itself.

 

[kiwi dave]

I was given the demo Griso to use by my dealer when my bike was being serviced. The clutch slipped badly, and I was fortunate to be able to return it without incident. I asked later what the problem was, and was told some twat had tweaked the adjustment on the lever way out of wack. Not sure how this might affect things, but a simple thing to check.

 

[xenarchi]

Moved from wrong topic per request...written by GrahamNZ

Sound principle - First, fish your feet.

In this case that means checking the simplest possible causes first, like checking that the gearbox hasn't been overfilled and that the level isn't too low. Too high may mean that whoever serviced the bike recently may be liable. Too low may mean failure of the gearbox input shaft seal allowing oil into the clutch area. Oil on friction surfaces which are meant to be dry can cause slippage, squeel, and even grabbiness. Too low can also mean failure of the gearbox shaft output shaft seal, which can be determined by removing the CARC (easy) and seeing if oil is running down inside the swinging arm.

All OK? Then is the clutch making its rattling music when the lever is pulled back and silent when released as it should? If not then the master cylinder or slave cylinder may have a fault. Siezure of one of them could be holding the clutch partly disengaged as Pete outlined.

When all else has failed, it's time to bite the bullet and inspect the clutch itself.

 

[GrahamNZ]

I was given the demo Griso to use by my dealer when my bike was being serviced. The clutch slipped badly, and I was fortunate to be able to return it without incident. I asked later what the problem was, and was told some twat had tweaked the adjustment on the lever way out of wack. Not sure how this might affect things, but a simple thing to check.

I don't see how adjusting the lever throw provided by the adjuster wheel could cause a problem. However there is often a "hidden" screw adjuster on a master cylinder which contacts the cylinder piston end that a determined idiot could find, access and alter. Maybe the Breva has that system but I never looked because I never needed to.......

 

[kiwi dave]

I was given the demo Griso to use by my dealer when my bike was being serviced. The clutch slipped badly, and I was fortunate to be able to return it without incident. I asked later what the problem was, and was told some twat had tweaked the adjustment on the lever way out of wack. Not sure how this might affect things, but a simple thing to check.

I don't see how adjusting the lever throw provided by the adjuster wheel could cause a problem. However there is often a "hidden" screw adjuster on a master cylinder which contacts the cylinder piston end that a determined idiot could find, access and alter. Maybe the Breva has that system but I never looked because I never needed to.......

I agree, Graham. I was just reporting what the shop told me. But I can't imagine a tweaker would bother chasing the "hidden" screw on the shop floor.

It reinforces why I'm reluctant to take my motorcycle to this shop, even for warranty or first service work.

 

[GrahamNZ]

Dave
Could it be that being a Griso without a centrestand, someone had topped up the gearbox oil to the bottom of the filler hole with the bike on its sidestand? That would be a good start in achieving a Pete Roper clutch slip.

 

[torino54]

Exactly right. I believe the shop over filled. Put it on the centre stand and oil came poring out. Took it for a short ride with no evidence of slipping. Hope to take a longer ride today weather permitting. Thanks for all the tips. I'll let you know the outcome

 

[john zibell]

Exactly right. I believe the shop over filled. Put it on the centre stand and oil came poring out. Took it for a short ride with no evidence of slipping. Hope to take a longer ride today weather permitting. Thanks for all the tips. I'll let you know the outcome

Unfortunately your plates have already been contaminated with oil and it is just a matter of time before they become a problem. Try to get the shop to own up to their mistake and replace your friction plates, plus remove contamination from the hub gear, pressure plate, intermediate plate, and ring gear. If they don't you will be faced with this task in the future, and there is no way to predict when that will be.

 

[GrahamNZ]

Oh, dear! I concur with John's sound advice. Surely the mechanic had the bike upright when draining the oil? If not then all the old oil wouldn't have been removed either. If he did that and then added the specified 500cc it would explain the overfilling too.

It's for reasons like that, that about 50 years ago I "bought my own spanners". Now who would pick an architect having a spanner, let alone knowing how to use it? Stanger things have happened, including a high-court judge frined of mine who rebuilt vintage cars with great expertise, so not being a trained mechanic isn't necessarily an impediment. Until now I've never owned a bike I couldn't maintain myself. There are competent mechanics out there of course, but finding them can be more of a challenge than learning to do the maintenance yourself. A sad state indeed. When you do find one, treasure him. The only maintenance I don't do myself is to have tubeless tyres fitted to the wheels, which I remove and replace myself. One of my riding mates (aged 73) even changes his own tubeless tyres!

The tuner's principle of "assume nothing and check everything" should be the mantra of everyone working on vehicles. "Reading and following instructions" is another sound principle.

 

[Cat City Rider]

Nothing a tad over 2K USD won't fix, parts and labor. Don't ask how I know. Your rear main seals most likely may be gone as well as the clutch. If the plates are slipping, they have turned a lovely shade of blue and have gone to the that great Guzzi resting place in the sky.
I'm no expert here but special tools are involved.

 

[john zibell]

Nothing a tad over 2K USD won't fix, parts and labor. Don't ask how I know. Your rear main seals most likely may be gone as well as the clutch. If the plates are slipping, they have turned a lovely shade of blue and have gone to the that great Guzzi resting place in the sky.
I'm no expert here but special tools are involved.

Why would an overfull transmission relate to the rear main? Besides, oil from the rear main can't get to the clutch, it is housed in the flywheel.

 

[Cat City Rider]

Nothing a tad over 2K USD won't fix, parts and labor. Don't ask how I know. Your rear main seals most likely may be gone as well as the clutch. If the plates are slipping, they have turned a lovely shade of blue and have gone to the that great Guzzi resting place in the sky.
I'm no expert here but special tools are involved.

Why would an overfull transmission relate to the rear main? Besides, oil from the rear main can't get to the clutch, it is housed in the flywheel.

The rear main engine seals. The crankcase was overfilled. My fault, I should have been more careful when installing a aftermarket dipstick extender. I actually believed the full mark to be accurate. Silly me. Not exactly sure if that was the cause but most likely as it started with more oil coming out of the breather overflow tube than normal. I went back to the (now available) factory extended dipstick and the overflow breather tube oil was cured, however, possibly too late, the damage was done. Oil found it's way to the clutch and poof! 2k later it's almost fixed. I say almost because the shift linkage may need a little adjustment. I am taking the bike back Wednesday for a little touch up work.
I reread your tale of woe and related my engine seals with your trouble. Wouldn't a blown front transmission seal allow oil to find it's way to the clutch as well? and yes a rear main engine seal will trash the clutch. I saw the results and the oil on the floor. But I'm no mechanic.

 

[john zibell]

Cat,

If the front transmission seal fails, there is a direct shot to the clutch plates. When the gearbox front seal fails, automatic clutch job as well. I've seen plenty of leaking engine rear mains on Tonti and loop bikes, but there is a drain hole. The space between the engine and transmission would have to fill allot to get oil on the plates from a rear main leak.

 

[Penis Rotor]

The Nuovo six speed has a huge slot at the bottom of the bell housing. It'd be hard to fill it up to the level of the plates. Engine oil from the main can contaminate the plates sometimes but if the clutch starts to sli[p early in the piece there is usually another contributor factor.

I can't see how people can over-fill their gearbox so drastically?? The instructions are in the book on how to do it, as are the oil quantities required. IMHO filling to the lower lip of the filler hole won't hurt anything. I see lots of bikes where that has been done, but all it takes to do it right is a measuring jug. How hard can it be???

Pete

 

[rturo]

I have a simple policy to stop me doing damage when refilling with oil. Use the capacities in the book as a guide to the maximum thats likely to be needed but always measure whats coming out as a guide to what likely to be needed.

I just drained the CARC and measured 350ml (10% less than 380ml in the book). I put in 350 and the level was right were it should be. I had warmed it up first and let it drain well, even span the wheel by hand to try and clear the oil off any top surface..

Now half way through the engine oil change and only 2.6-2.7litres came out including that in the filter (it was at the half way between min n max on the dipstick) .. again fully warmed up (nearly lost skin in the bloody cat removing the drain plug.... and let it drain on the centrestand until it was cold... i even moved the bike left and right and back wheel to the ground to try and get it all out ... could there be that much oil clinging on somewhere in there or could my dipstick reading be that wrong (unscrewed after a warmup run)....... even so only 2.7litres will be going in before I start checking the level and take it from there

Art
B11