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Anybody recognize this knocking sound?


Hansson

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Thanks. I've used the Staburags on the Guzzi driveshaft splines - I think that's the ideal application. 

 

If I don't feel like buying MIL-spec sprays, I assume any dry moly spray, like CRC's would do. Do you spray all four surfaces: flywheel, transmission gear, clutch disc inner teeth, and clutch disc outer teeth? (obviously masking the friction plates).

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Thanks. I've used the Staburags on the Guzzi driveshaft splines - I think that's the ideal application.

 

If I don't feel like buying MIL-spec sprays, I assume any dry moly spray, like CRC's would do. Do you spray all four surfaces: flywheel, transmission gear, clutch disc inner teeth, and clutch disc outer teeth? (obviously masking the friction plates).

I agree, Staburags grease would be great for the spline couplings at each end of the driveshaft. It would squeeze out to allow the splines to clamp together tightly, but still exclude air & water, to reduce fretting corrosion. Drylube in that joint could crush away to allow the spline clamping to loosen, and rapid wear might be next.

 

The spline in the middle of the driveshaft needs regular thin grease, as it slides a lot, and clearances are too tight for a layer of dry lube.

 

The spline from the bevel box to the cush drive can benefit from both dry lube on all contact faces, and when cured, Staburags or similar HT moly grease. It is not a tight spline, so a buildup of drylube is a good thing. My bike is very worn there so lube can only delay the inevitable parts replacements. But still it is plastered with drylube, including the cush drive parts & rubbers, then the spline is greased.

 

CRC Dry Moly is probably fine, especially for your rear wheel cush drive spline, since you can reapply at every tire change. I don't know how durable it is longer term in the clutch, which is harder to access, but still anything is better than nothing.

When I get to the clutch on my bike, I will drylube the clutch parts just as Tim described.

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When this is done you should use a dry film graphite spray or a good anti-seize lube on the splines on anything with splines.

 

Can you say more about that? I mean, would you basically spray the whole inside of the flywheel and the transmission input gear? And do you mean anti-seize paste - like the silver (or copper) stuff you put on bolt threads? My BMW specifies a Staburags (NBU 30 PTM) grease for the splines, which is so thick and sticky you have to brush it on. But the splines on the BMW are tiny in comparison to the Guzzi splines. I have some of that.

 

I just put a clutch back together yesterday, but didn't lube it. It's easy-access now... any extra advice appreciated.

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Here's my experience with lubes on the splines. To make a long story short, I tore a strada down shortly after putting it back together chasing a mystery vibration.

Now, every Guzzi I've had apart has had rusty splines, so on the advice of Wayne Orwig, I made up a slurry of chain lube and moly and applied it to the splines with an acid brush. Obviously, you don't want to put so much on there that it gets flung onto the clutch plates.

After putting it back together, the mystery vibration was still there, so Itore it down again for a complete balance of the rotating assembly.

Less than 1000 miles, and there was no sign whatsoever of the lube I'd put on. Need I say that I don't bother anymore? :)

Now, about that clutch plate thing. Because of the uneven firing order (270/450) she soundsa good.. :) but when the springs are compressed the clutch plates and intermediate plate are free to rattle back and forth on the flywheel and transmission input splines. This will eventually wear grooves in both sets of splines. The first sign the rider sees is a clutch that suddenly engages.Once that happens, there's no option but to replace stuff. Those splines will last forever unless you hold the clutch lever in for extended periods.

Oh, the mystery vibration? Sometime in it's life, it had been down on the right side and bent the crash bar enough to cause a sympathetic "singing" for want of a better description. :)

D'oh!

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I don't kmow how I wrecked my edit but I will try again . 

You will need to disassemble this and apply lube to all splined areas . FIRST you must remove all rust and clean the areas because rust is a great abrasive . I would apply lube to the release fingers and clean and lubricate the release bearing with a good disc brake wheel bearing grease .

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I don't kmow how I wrecked my edit but I will try again . 

You will need to disassemble this and apply lube to all splined areas . FIRST you must remove all rust and clean the areas because rust is a great abrasive . I would apply lube to the release fingers and clean and lubricate the release bearing with a good disc brake wheel bearing grease .

Only the Guzzi system doesn't use an automotive type release bearing and yoke. The release bearing is at the back of the gearbox nd is acted on by the piston of the slave cylinder directly.

 

On the subject of lubricating the splines? I'm with Chuck nowadays. I see lubricating them as pointless and if too much slippery is applied actually counter productive.

 

On the subject of the noise? I haven't been able to view the video but looking at the flywheel I'd say it's been the victim of three things.

 

1.) What Chuck described.

 

2.) Poor throttle body balance.

 

3.) Too low an idle speed.

 

If your idle speed is low and the TB balance is off the rocking couple caused by the uneven firing intervals will be greatly exacerbated. Any 'Knock' will most likely be the primaries in the gearbox flogging to and fro as the input shaft accelerates and decelerates with the crank.

 

Give it a tune up and get the idle speed up to a minimum of 1100rpm. See if that fixes it.

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I have found Dri-Lube Plus to be the best dry film graphite spray . www.certifiedlabs.com is the website . When anything is applied to anything you must used conservative amounts as with anything.  

Pete you should listen / watch the video . I think you will agree it needs to come apart and repaired .

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  • 5 weeks later...

Update.

 

I think I've found the cause, from where the noise comes. There is backlash between the gears of first gear. There is also a small backlash between the gears of the second gear.  https://drive.google.com/open?id=0B1cTu58Dx28vTmFlY2lkVEl0aFE

 

This, I think, may be due to worn gear and/or worn needle bearings. There is no visible wear on the gears, but tolerance is perhaps small. I suppose it's difficult to measure the wear on the gears. I don't think the gears should be worn after just 34000 kilometers (21250 miles). The gearbox oil has been changed regularly every year. If I want to replace gears and needle bearings, it will be costly. Around 1200 euros. If I'm right, you can't buy gear for the first gear on the input shaft itself, so you have to buy a complete primary gear shaft assembly. This shaft will cost 680 euros. But I might take a chance on, only replace needle bearings.

 

The flywheel, I will probably replace with a beautiful Ergal aluminum flywheel. Price about 500 euros.  Flywheel%20alu_zpsf8caoivj.jpg

Of course I will also replace the clutch gear, although it is not particularly worn. 

 

I must admit that I'm little about to lose hope of this bike/make. Bad quality of parts and/or poor construction? Having to dismantle half the bike just to get access to the clutch or gear box is not fun... Don't try to come up with "there's no need to do that often."  :rolleyes: But yes, I also love the bike :D!!

 

Ciao 

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I can't see how the tranny gears can make the noise in your original video. More than likely the clutch/flywheel. BUT, I would advise a friend to do what Pete Roper suggests -First and always-.

 

If you are referring to this footgoose.. The TB balance, AFR balance, valve clearance and idle speed is super tuned. Recently run in bench. The compression is perfect and in balance.

 

Can't you see Pete Ropers explanation "Any 'Knock' will most likely be the primaries in the gearbox flogging to and fro as the input shaft accelerates and decelerates with the crank." ?

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Watched first video    I got nothing  :huh2:

second video ...everything appears normal to me ....always going to have a bit of play 

with gears,shafts, and meshing together.

even straight cut gears have a little bit of "play" in the box.

The unfortunate way to check the gears is to disassemble the box so you can check the

splines on the shafts and gears.

andy

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...flywheel, I will probably replace with a beautiful Ergal aluminum flywheel. Price about 500 euros...

That flywheel looks like a work of art alright, but I worry that you may be disappointed if you fit it.

Aluminum is not durable as a flywheel material. It would be great for racing, where frequent inspections and rebuilds occur, but it cannot last as long as a steel part. 

There are some reasons why aluminum is not used in most flywheel designs. 

Aluminium is weaker than steel and softer than cast iron. There are some very strong aluminum alloys, but these are susceptible to corrosion and stress corrosion cracking, so need surface protection and frequent inspection.

Alum does not have a fatigue limit like steel, so it will eventually crack from the constant load reversals from the engine compression/power strokes from those two cylinders.

The surface of alum can be made hard enough for wear resistance in the contact faces of the clutch rotor teeth by hard anodising, but still wear in those teeth will exceed that of the factory flywheel.

The inertia is important too. An alum flywheel has less rotational inertia, unless the manufacturer does something clever with a thicker rim. If there is less inertia, then the torsional vibrations through the drive train will be greater (worse for your gear backlash). 

I don't want to be a downer, but you should be aware of these things before spending money on an aftermarket product.

The factory flywheel & clutch is a well optimised design, if you ride on the street, and value durability, tractability, and cost.  

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Update.

 

I think I've found the cause, from where the noise comes. There is backlash between the gears of first gear. There is also a small backlash between the gears of the second gear.  https://drive.google.com/open?id=0B1cTu58Dx28vTmFlY2lkVEl0aFE

 

This, I think, may be due to worn gear and/or worn needle bearings. There is no visible wear on the gears, but tolerance is perhaps small. I suppose it's difficult to measure the wear on the gears. I don't think the gears should be worn after just 34000 kilometers (21250 miles). The gearbox oil has been changed regularly every year. If I want to replace gears and needle bearings, it will be costly. Around 1200 euros. If I'm right, you can't buy gear for the first gear on the input shaft itself, so you have to buy a complete primary gear shaft assembly. This shaft will cost 680 euros. But I might take a chance on, only replace needle bearings.

 

The flywheel, I will probably replace with a beautiful Ergal aluminum flywheel. Price about 500 euros.  Flywheel%20alu_zpsf8caoivj.jpg

Of course I will also replace the clutch gear, although it is not particularly worn. 

 

I must admit that I'm little about to lose hope of this bike/make. Bad quality of parts and/or poor construction? Having to dismantle half the bike just to get access to the clutch or gear box is not fun... Don't try to come up with "there's no need to do that often."  :rolleyes: But yes, I also love the bike :D!!

 

Ciao 

I just re listened to your video and your bike sounds just like mine, flick the clutch quickly and it stops clattering for a bit when the plates realign and then after you cycle the clutch it starts up again. Meh, mines been doing it since day 1. I'd forget the gearbox and go with the Aluminium flywheel. MartyNZ made some valid technical points about aluminium as a material but its mostly irrelevent in the grand scheme of things with regard to the flywheel. A bit like the argument about how bad telescopic front forks are, technically valid but more honoured in the breach than the observance, so to speak. Ducatis have used aluminium baskets as have Japanese bikes for many years and fatigue failure is not a realistic worry. Neither is wear really with the exception of the dry clutch Ducatis and even then they last for 30,000 or so Klms before replacement. The Guzzi however has far more toothed surface area so its life would be many times greater. Besides unless you spend all your time commuting or towing a sidecar around then the std flywheel assy is a massivly heavy joke and needs to be ditched for something lighter. Even the lightest V11 flywheel is in my opinion way too heavy.

 

Ciao 

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