CARC rear bevel internal friction

[vuzzi]

I recently took the rear bevel box of a griso 1100 (2008) for reagular maintenance of the rear parts. I notice that, when rotating the ingoing shaft of the box, the resistance is quite big. Much bigger that the one of a v11 I happend to have in stock. It's quite hard to turn it around with bare hands

 

I opened the box, but couldn't see any signs of wear.

 

Is the high friction normal? Is the high friction caused by the reaction mechanism?

 

[pete roper]

No, but the pinion bearing preload is set by a collapsible spacer so it's higher resistance than the solid spaced bearings of earlier boxes, (If set up correctly.) also the bearings themselves are more numerous and much, much larger than in previous designs.

 

The CARC box is pretty much indestructible. I've covered the major things that should be checked and a few bits of preventative maintenance like loctiting the pinion nut on other boards but apart from the early batch of crappy crownwheel support bearings and the occasional pinion nut dumping it's preload they are so massively over engineered you can't kill 'em with a shitty stick!

 

Pete

[swooshdave]

Now I need to get a CARC and see if I can prove Pete wrong. 

[docc]

Now I need to get a CARC and see if I can prove Pete wrong. 

Sounds like you'll need a major-league *shitty stick* for the testing protocol.

 

(Wear eye protection. Maybe one of those NBC suits for the inevitable splatter . . .)

[pete roper]

More bad luck than shitty stick but it still enrages me that a.) they don't use Loctite on the fucking pinion nut and b.) we aren't allowed to buy the spacers, pinion shims and the rest of the crap to properly rebuild these great lumps 'O munt!

 

Pete

[Chuck]

I've never even seen the inside of one of those boogers, but Shirley the shims and spacers could be fabricated? Or are they more complicated than that?

[pete roper]

Shims can certainly, the spacer is a sort of glorified wavy washer, well not so much 'Wavy' as 'Corrugated', I'm buggered if I could think of a way of manufacturing them in small batches. I feel the pinion shims are probably the same as the V11 ones, they go under the pinion support bearings in the *Neck* of the reactive bridge. The collapsible spacer goes between the two pinion bearings. On the ones I've had apart there seems to be no provision for shimming the crownwheel. Adjustment for backlash and one assumes mesh seems to be done solely by moving the pinion in and out, something that is probably OK given the monstrous oversize of the teeth. There is probably heaps of toe and heel coverage so you only have to worry about face and flank. (For those unfamiliar with setting up spiral bevel sets the old maxim is 'Face and flank? Move the crank, [The pinion.] Toe and heel? Move the wheel, [The crownwheel.].)

 

What shits me Chuck is that they won't just sell you the bits. I've got a perfect CW&P set up sitting in the bench that is unusable because I can't get a couple of stupid little parts and can't work on it how to get the phenolic type cage of the pinion nose bearing out of the reactive bridge without arseing it up! I do know that there is heat used in assembly as the pinion bearings are a tight interference fit in the neck of the bridge and have to be seated correctly on their shims and register otherwise the nut will loose it's preload when the box gets hot, (Which is what occasionally happens.). It's all part of this ongoing and creeping acceptance of the de-skilling of the workforce. Rendering more and more people into the thrall of planned obsolescence.

 

One of the blokes I drink with at the Royal has just retired. He spent most of his life building differentials for high performance vehicles. Now he's pulled down the shutters. He couldn't find ANYONE who either had the skills or the desire to learn them to take over the business! How sad is that??? I'm just so glad I've got Michael on board. Not only is he a skilled tradesman in his own right but he's keen as mustard to learn new stuff AND likes Guzzis! I feel like I've been kissed on the arse by a golden fairy!

[Chuck]

 

 

the spacer is a sort of glorified wavy washer, well not so much 'Wavy' as 'Corrugated', I'm buggered if I could think of a way of manufacturing them in small batches.

 

What material? 

 

 

 It's all part of this ongoing and creeping acceptance of the de-skilling of the workforce. Rendering more and more people into the thrall of planned obsolescence. 

Part of this is by design, maybe.. but much of that is there just isn't a skilled workforce any more. At least here in the states. Manufacturing went overseas in the 80s and 90s, and there weren't any young people joining the trades. Chrysler has been bugging a friend to come be a tool and die maker for them, and he's in his 60s. (!) They can't find any one..

I'm just so glad I've got Michael on board. Not only is he a skilled tradesman in his own right but he's keen as mustard to learn new stuff AND likes Guzzis! I feel like I've been kissed on the arse by a golden fairy! 

 

Well, I don't know about the fairy thing, but you lucked out, there all right.. 

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[68C]

Pretty much the same in the UK. The local Ironmongers/Hardware shop don't sell anything really useful now, just decorating stuff and cheap basic tools. No more selection of nuts and bolts, metal stock or even proper paint stripper. The trouble is nobody mends anything any more.

[pete roper]

Chuck, I think it's made out of some sort of mild steel but I'm not sure. Maybe a spring steel? It's able to be crushed beyond its limit of elasticity quite easily I found out!

[vuzzi]

Thanks fot the replies. My question brought up some additional interesing questions and thoughts. But for me for now I don't see any need to open up the rear drive bevel again. I'm waiting for the snow to disapear and hope for an opportunity to ride soon.