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Clutch not fully releasing - and shifting problem


Scud

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IMG_5941.jpg

 

I got this transmission from eBay. The tranny was $500 and the seller said it was from a Nero Corsa, was in good shape, had about 20,000 miles, and had never been opened. 

 

I bought it a few months ago - in response to getting dealer quote of $500 just to open and inspect the transmission from my LeMans - and that was if I took it out of the bike. That was from the local BMW dealer who recently stopped carrying Moto Guzzi. That was also before I had gotten into a tranny for the first time and I was still intimidated by it. 

 

So, it cleaned up pretty well, and what I thought might be a leak appears to have been accumulated gunk. I gave it a quick flush with diesel fuel to get some more of the Redline heavy out.  Cleaned the sight glass and breather, cleaned out the slave cylinder cavity. And the (nearly unobtainium) slave looks in good shape.

 

The verdict - it runs through all the gears and there is no perceptible play of the output shaft in any gear, nor in neutral. If this transmission works, I'll do an autopsy on the other one to see why it's been having a hard time with 3-4. And maybe LowRyter will get a transmission case to paint silver for his leaky greenie.

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The season finale of The Bachelor was on tonight, house full of women... so I did some research... in the form of a canyon blast under a full moon and the scent of nigh-blooming jasmine. Gosh, that makes it sound like something from The Bachelor.

 

Focused on the 3>4 upshift and what's going on that causes occasional missed shifts.

  • The harder I'm accelerating, and quicker the clutch action, the more likely I am to miss the 3>4 upshift.
  • If I back off the throttle in 3rd gear enough to allow mild engine braking (even for a fraction of a second), the 3>4 upshift goes in easily.

Good news: knowing this makes it much more rideable - I just have to adjust my habits a little.

Bad news: this seems like a problem deep in the gearbox, not a pre-selector issue - which makes swapping trannies even more likely.

 

All thoughts, insights, speculation, or ridicule welcome. What could be going on inside the tranny to produce those symptoms?

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Thanks Marty. I went and re-read that thread. I made several posts in there, which are about the same bike as this thread. I never did touch the eccentric adjuster. I could do that - or even swap the whole pre-selector from the other tranny, instead of swapping the whole tranny.

 

This is the kind of thing where it would be nice to have someone who knows what they're doing ride the bike. It's probably something simple - just as the clutch problem was solved by different springs.

 

But I'm still puzzled by the fact that engine braking in 3rd followed by upshift to 4th is smooth - whereas running briskly through the gears under acceleration (with normal clutch and slight release of throttle) causes a false neutral (missed shift) between 3rd and 4th.

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All thoughts, insights, speculation, or ridicule welcome. What could be going on inside the tranny to produce those symptoms?

 

No ridicule. It is very hard to put into words what is going on. There is a lot of slop/freeplay in the transmission.Under full load its pushing the gear stacks farther away for the next gear shift. A slight off throttle will "relax" the the gear stack and make it easier to engage the next gear.

Do you have Chucks plate on the shift mechanism ? I would have thought that this would give more leverage for the shift lever and eliminate this problem.

​I don't really know if you can shim these boxes like the old 5 speeds. Maybe Pete will chime in here.

andy 

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Thanks Marty. I went and re-read that thread. I made several posts in there, which are about the same bike as this thread. I never did touch the eccentric adjuster. I could do that - or even swap the whole pre-selector from the other tranny, instead of swapping the whole tranny.

 

This is the kind of thing where it would be nice to have someone who knows what they're doing ride the bike. It's probably something simple - just as the clutch problem was solved by different springs.

 

But I'm still puzzled by the fact that engine braking in 3rd followed by upshift to 4th is smooth - whereas running briskly through the gears under acceleration (with normal clutch and slight release of throttle) causes a false neutral (missed shift) between 3rd and 4th.

As I mentioned in my selector rework thread I would never attempt to adjust the excentric on the bike,its way too sensitive for that.Try pulling it off and adjusting it on the bench. It adjusts the relationship between the shift stop and gear selector travel. I found that you can actually adjust it so that in some gears it will underselect the gear and conversly overselect another and fully select the gear and then start to actually pull it out of gear before detenting.  It's then up to the gear dogs to drag it fully back into engagement.Try pulling it off the trans, put it on the bench and run through the selecting and you will see the relationship I'm talking about and see how it is in the 3rd to 4th selection. If its not great then adjust the eccentric to optimise this pair even if it compromises another pair a little. I actually added some weld to the stops on one of my transmissions. 

Hows it up shift 3rd to 4th without the clutch Scud?

 

Ciao

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I have installed the Phil 'n' Chuck shift extender on the foot lever/linkage. The overwhelming majority of shifts are smooth.

 

I can get clean 3>4 clutchless if I engine brake 3rd, but it will usually miss if I shift under acceleration (with small throttle dip). I can get clean clutchless 4>5>6.

 

I have also felt an occasional clonky, abrupt downshift in some lower gears, but I have not figured out exactly which gears or the conditions that cause it - and as Andy noted, it's kind hard to describe.

 

Here's the layshaft diagram at Harper's website.

 

http://www.harpermoto.com/parts-by-motorcycle/2000-up-moto-guzzi-motorcycles/v-11-cat-1100-2003-2004/driven-shaft-en-v11-cat-1100-2003-2004.html

 

The gears are arranged on the two layshafts like this:

 

Front   ----1--5----3----   Rear

           --4-------6----2-

 

Gears 4 is very far forward of gear 3, maybe that has something to do with why 3>4 is a problem (if the stacks are compressing under acceleration).

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IMG_5941.jpg

 

As I said here, back in 2003, ya'll are The World's Foremost Experts on the V11 6Speeder! :notworthy::thumbsup:

 

I love this photo - so much going on. The Knolling of the tools, the V11 Workshop Manual in the background, a full-on ball-peen hammer, adequate toweling (don't tell mama!), LED flashlight, and Nitrile gloves are all so reassuring  .  .  .  . 

 . . . .  then the troubling *Leavenworth* coffee mug shows itself. :huh:

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That's how I knoll, baby.  :grin:

 

I do some work for the US Army in Fort Leavenworth once or twice a year. The joke, of course, when one goes to Leavenworth, is: "Why, what'd ya do?" To explain for members outside US, there are a few prisons in Fort Leavenworth, including a Federal Penitentiary and the Army's maximum security prison. If you get sent to Leavenworth, you're gonna be there a while.

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"Born in Leavenworth" . . . :whistle:

 

That says something about a guy . . . ;)

 

 

Yup.... did 5 years there as a toddler. Then we got sent to Alcatraz. I did a year there. Got out for being quite small and very polite. All these years later... a Guzzisti!

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Pulled the pre-selector off the LeMans (on right) and off the spare transmission (on left).

 

IMG_5947.jpg

 

The LeMans preselector goes through all the gears on the bench, up and down.  So I'm really unsure what I would adjust.

 

The spare also goes through all the gears, but it feels even tighter and crisper. And the spare has a metal banana on it.  I think I've seen something about this being standard on the 2004 bikes, and that there was an upgrade kit available for the earlier bikes.  So... is there any reason I shouldn't just put the newer preselector in?

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