Stelvio broken gearbox shaft

I was touring in Scotland until suddenly the bike dropped, while approaching a roundabout. I was surprised, because I was braking hardly. The driver footrest broke and some damage that you get when such things happen. So I put the other footrest at the driver position and wanted to continue my trip. I started and put in gear, and the bike stayed where it was. I started examining the bike, put it on the stand and turned the wheel, something loose in the swingarm it sounded. A friendly local motorcyclist offered to put the bike in his garden to examine further. So we did, went to Halfords to get a tool to dismount the rearwheel, and in 10 minutes it was clear: the outgoing shaft out of the gearbox is broken. My insurance brings the bike back home, and paid the tickets to fly home.
The broken shaft made the cardan shaft rotate in the swingarm and locked the wheel momentarily, that made me drop with the bike.

So this is what it looks.
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Well that's a first! Bad luck, one can do Bly assume some sort of metallurgical flaw.

Pete

Pete, how much work is it to change that shaft from the gearbox, besides getting the box out? Tooling needed?

I see the shaft is 225 euro, or can I better get a used box for more?

Paul, how many kilometres have you done?

62000km

Agostini Mandello sell cheaper drive shafts from time to time - check their specials page on their Webshop. Otherwise, there's the used ones from the usual suspects - TLM, Reboot, etc if the new price is a stretch. Good luck.

This is the first time I've heard of this sort of problem with a 1200-8V box. They are usually bulletproof. In fact all the 'Nuovo six speeds' are tough as buggery, I've only ever had one 1100 box apart and that was simply out of curiosity.

As for taking it apart? There are a couple of special pullers to assist with separating the cases, I can lend them to you if you like?

Thing is €220 for a shaft is a lot of money. As a 'Thank You' for all the hard work with Guzzidiag I'll send you a complete gearbox, I'm sure it won't cost a lot more than €220, probably less. I have three or four low mileage boxes, because they are so damn reliable it's unlikely I'll need that many. if you want to rebuild yours as well I can fling the pullers into the box with the gearbox and you can split your cases and post 'em back.

Send me an address and I'll drain one and take it to the shipper on Monday.

Just make sure you take lots of pics of what the insides look like on yours if you have it apart. As I said I haven't been inside one that's done a few miles. I'd like to have a squizz at what might or might not wear.

Just cover the freight charge.

Pete

Oh, one other thing? How are the trunnions in your driveshaft? Do they have any side to side play in the crosses in the caps? They are assembled with shims beneath the circlips that hold the caps and if one of these escapes it will throw the shaft off-centre which will impart a small but maybe significant out of balance factor to the assembly which could possibly of contributed to the shaft failure if there was already a defect in the shaft.

Incidentally I went and sourced what I believe are the correct couplings for the CARC driveshafts from Specialties in Canberra on Friday. $30 each is a shitload better than the cost of a new shaft!

Pete

Pete, I had the shaft in my hands last year when I changed the swingarm bearings. It felt like new. No play that I could feel. Then at 55000km I think. The shaft did have some play on the splines, but didn't feel a lot. As could be seen, I greased it at mounting. Mostly to make it not rust and keep metal on metal away to reduce further grow of the play.
I will look at the swingarm inside, how much damage it has from the shaft. And the same for the shaft outside, there is some abrasion at the end.

The bike is not at home yet, so there is time to explore what is the best way to solve this. And first thing is getting an estimate from the insurance people on the damage the bike has from hitting the ground. The offer of sending one box over is great.

I've got a spare swingarm too if you need it.

what a nice thread to read.

Confusing..... looks like a fresh complete torsional failure .....
No indications of earlier commencement of failure
Most show indications of cross sectional area 'patches' of discoloration indicating an earlier commencement of impending failure
Very unusual ...
No wonder he failed to keep forward motion going
Try to keep smilin

First thing I thought was torsional failur. Second thing I thought was also torsional failure!

I've seen identical failures before on the pinions of V11 bevelboxes but in all those cases the trunnions of the Hookes Couplings in the shafts weren't aligned properly. That isn't supposedly possible with the CARC shafts due to their bonded construction.

It's definitely a torsional failure. The question is why? And that we may never know.

Pete

The metal doesn't look grey, some coloration also, but maybe just the picture. I can't remember.

From the garmin logs I can see I was at 20 km/h and then in 2 meters it was zero. Before that I was slowing down from 40km/h

The rest to repair(might be more):
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Got the bike back yesterday so now the gearbox is out.
Now I'm thinking, should I change the clutch too when it's open. 62500km now. I also have an almost new clutch but 2012 there were issues with some.



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I did try to leave the main stand on, to support the engine, but in the end it was blocking the way out for the gearbox.  

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A lot of work Paul, best of luck with it.  I think I would replace the clutch if it has over 60k done. Wouldn't want to have to strip it again for awhile

The offer's still open on another box Paul.

If you replace the shaft you really need these two tools.

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They make splitting the cases an effortless, damage free, breeze.

Also note that the pawl mechanism is really quite fragile. If it bends it won't allow the jaws to move freely so take care.

You also mentioned that insurance might cover it? Anything more on that?

Pete

I love pictures of surgery...
Oh, and I'd replace the clutch if the bike is not declared a total loss.
Easy to get to it now...

I'd just take the plate out and measure it. If you would like a nice, light, clutch pull fling in the latest Cali 1400 unit. It's lever action is super light and delicious! I just bought one for the 1400 build for Beetles bike having forgotten he has a radial clutch master so he doesn't need it!

Pete

pete, what is different on the 1400 unit, must be some part?

Do you know what the thickness is of a new plate?

My plate is 6.2mm, one from a 2012 clutch with 4500km is 6.6mm.  

Few options:

mount a new plate  (90 euro)
mount the 2012 plate (free)
mount the 2012 clutch complete (free)
mount cali 1400 clutch (640 euro)

the 2008 flywheel is 400 gram more heavy than the 2012 model.

pauldaytona wrote:

Pete, I had the shaft in my hands last year when I changed the swingarm bearings.

I don't know about you Paul, but generally speaking, I need to use both of my hands when working on the Stelvio.  That said, if you can manage it, bravo my friend, bravo...

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pauldaytona wrote:

pete, what is different on the 1400 unit, must be some part?

Do you know what the thickness is of a new plate?

My plate is 6.2mm, one from a 2012 clutch with 4500km is 6.6mm.  

Few options:

mount a new plate  (90 euro)
mount the 2012 plate (free)
mount the 2012 clutch complete (free)
mount cali 1400 clutch (640 euro)

the 2008 flywheel is 400 gram more heavy than the 2012 model.  

My guess is the spring diaphragm as the pull is much lighter but I have an early and late clutch in stock so I'll try and measure the plate thickness today.

Pete

Steak wrote:

pauldaytona wrote:

Pete, I had the shaft in my hands last year when I changed the swingarm bearings.

I don't know about you Paul, but generally speaking, I need to use both of my hands when working on the Stelvio.  That said, if you can manage it, bravo my friend, bravo...

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Yesterday was gearbox repair day. All went smooth. Only inside soem more surprises. Two gears, I think you call them dogs, were not smooth anymore. So we swapped gears from the set that was laying there.

The dogs and a little bit the gear the go into were rough.
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My V11 LeMans Suffered a rear wheel lock up going into a corner with similar results. I was traveling a fair clip faster though. My mechanic thought it was probably a gearbox failure. When the insurance adjuster determined it to be a write-off, I let it go. It still nags at me not knowing what the exact failure was, but I am sure it was going to be a drain on the pocketbook to find out.
Watching this thread, it occurred to me perhaps the issue here may have started in the gearbox with the shaft shearing as as a result? You are welcome to jump all over me for offering this up; I am not a mechanic!