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Discussion Starter #1
Hi all,

I'm still chasing a rattle in my bike somewhere. I haven't yet narrowed it down to the alternator nut, but since my bike is a 2000 model, i may as well check it anyway. Questions:

1. My bike is 3-wire alternator model. Does that mean the alternator nut is unlikely to be loose?
2. When do you replace the nut instead of re-use?
3. What's the best way to secure the flywheel when tightening? I haven't got an assistant unfortunately..
3. After applying the threebond, does it matter how thick the sealing layer is? Is there any chance for the goop to pinch off and fly around inside?
4. Does it really matter if you use the official three-bond?

Sorry about the noobish questions! Past experience has taught me to ask first before I FUBAR it with assumptions.

Cheers,

bj.
 

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Hi all,

I'm still chasing a rattle in my bike somewhere. I haven't yet narrowed it down to the alternator nut, but since my bike is a 2000 model, i may as well check it anyway. Questions:

1. My bike is 3-wire alternator model. Does that mean the alternator nut is unlikely to be loose? No, they do come loose.

2. When do you replace the nut instead of re-use? When you screw it on & it isn't tight on the thread.

3. What's the best way to secure the flywheel when tightening? I haven't got an assistant unfortunately..There is a flywheel holding tool, fits in the holes around the edge. I just jammed a rag between the gears but that's not the recommended way at all so they tell me.

3. After applying the threebond, does it matter how thick the sealing layer is? Is there any chance for the goop to pinch off and fly around inside?
Just needs a very thin layer, I smear it on with a cotton stick.

4. Does it really matter if you use the official three-bond?
I use Permatex ultra grey, same stuff.

Sorry about the noobish questions! Past experience has taught me to ask first before I FUBAR it with assumptions.
Best way to find answers

If you take the left fairing off, start the bike then stop it whilst looking in the glass porthole you will see the flywheel wobble as it comes to rest if it's loose.
If you do retighten it (and I would anyway,) clean everything thoroughly and use red Loctite 263 high strength threadlocker.
I used a lesser strength the first time I did mine & it came loose again.
The first time it came loose it came completely off, damaged the nut, needle roller bearing and broke the thrust washer... you don't need that...
I chased a strange rattle in mine for a while and it turned out to be the steel ring around the alloy sureflex clutch basket had come loose.
 

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You really need to hold the fly wheel to tighten the nut . anything else can cause all sorts of problems , not least a fractured crank , I made my own it bolts to the holes in the flywheel and the side stand mounting holes .
 

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I've recently use the the regular high temp RTV I had at home. You wanna put a very thin layer: most of it will squeeze out.

In my case I didn't care how it looked so I used whatever I had which was red. The Ducati RTV is gray so you won't notice it.

Chris at CA Cycleworks sells a paper gasket if you'd like to go that route. The only thing is I would check with him if you have to reshim the can sensor.

As for the rattle, I dunno. The damn thing rattles everywhere!!! But a friend had the throttle shaft that had too much play in the bore and was rattling at idle. He was chasing a valve for the longest time before he found it.

Sent from my Nexus One
 

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Discussion Starter #6
I've also got my mechanics stethoscope now, so hopefully I can track that rattle down Dr Ducati style :D

I just realized I have one of these clutch hub holder tools:


Do you reckon the casing is strong enough to stand the alternator nut torque?

Another question: if the nut is not loose to the touch, should I just leave it alone? Or just torque? Or undo and re-torque?
 

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I've also got my mechanics stethoscope now, so hopefully I can track that rattle down Dr Ducati style :D

I just realized I have one of these clutch hub holder tools:


Do you reckon the casing is strong enough to stand the alternator nut torque?

Another question: if the nut is not loose to the touch, should I just leave it alone? Or just torque? Or undo and re-torque?

I would remove the nut regardless, degrease the threads etc - and refit with red threadlock/loctite...

Got my flywheel nut off a few months back by putting the bike in fifth gear with the front wheel in the garage corner, also had a foot on the back brake?

In typical Ducati style it will either come off easy - or be a real pig to loosen...
 

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I've also got my mechanics stethoscope now, so hopefully I can track that rattle down Dr Ducati style :D

I just realized I have one of these clutch hub holder tools:


Do you reckon the casing is strong enough to stand the alternator nut torque?

Another question: if the nut is not loose to the touch, should I just leave it alone? Or just torque? Or undo and re-torque?
Just take it out and put a new washer and nut, you can't reuse it. I think that Ducati has a diferent/better nut on the later models.
 

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An impact wrench will spin it off without a holding tool. You can toque it back up in 1st or whatever gear you prefer with your friend hard on the back brake.

I wouldn't reuse the nut. I did on one of my 748 engines and it backed off within 4k miles. But some say fine reuse it. Go with your gut. If you do get a new nut get the two piece kit from Nicohls. I have never had an issue with them.
 

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Its your bike so you can tighten the crank nut anyway you want but be warned these half baked ideas about putting pennies between gears or using the clutch holding tool or putting it in gear with the brake on CAN cause this .
 

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** Blowtorch the nut before trying to remove it - will ash up any threadlock previously used & save you chewing the threads up... ;)
 

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Discussion Starter #16
I've decided to take it to the shop. I bet I could do it, but that snapped crankshaft (?) has spooked me. To do it properly, I'd be up for a proper alternator holder tool or a compressor+rattle gun which is getting a bit to expensive for me. Knowing my luck, it's a more sensible choice :eek:
 

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Discussion Starter #17
Just getting ready to order a new nut. One last question: has the stock nut's oversize problem been fixed, or would I be better off getting a Nichol's nut pair?
 

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Its your bike so you can tighten the crank nut anyway you want but be warned these half baked ideas about putting pennies between gears or using the clutch holding tool or putting it in gear with the brake on CAN cause this .
That crack existed long before the crank snapped. It started at the bottom, probably at a spline root and progressed up the right side as can be seen by the "beach" marks in the metal. It may have snapped while tightening or loosening, but the crack was already there.
 

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Just getting ready to order a new nut. One last question: has the stock nut's oversize problem been fixed, or would I be better off getting a Nichol's nut pair?
You know, you're going to spend some change getting the left case taken care of, and you might as well go with the Nichol's nuts. I did it with my ST4s, since the desmoquatro engines are notorious for spinning their nuts off (not the same as getting your nuts off) at the wrong time. Davy-j, if I recall correctly, just caught his 748 in time. Others have not been so lucky.

Do have the mechanic use red loctite, and have him mark the nut with a red paint-pen, so that the next person going in there will not have to guess as to what's the deal. Have your shifter arm checked out and adjusted at the same time, and think about having the layshaft chintzy lockwasher replaced with a better unit. My mechanic did all three at the same time, and it's only a few bucks more than just looking at the alternator nuts.

Good feeling, knowing that there's no problem lurking on the left side of the bike.

Ron
 

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Flywheel Retaining Nut

Just getting ready to order a new nut. One last question: has the stock nut's oversize problem been fixed, or would I be better off getting a Nichol's nut pair?
In the early ‘90’s Ducati used two jam nuts to secure the flywheel on bikes like yours, but later replaced this design with a single very-fine-thread flange nut that carried with it an extremely high torque requirement.

On these later bikes, the factory installed defective nuts on some 1999 and 2000 model year bikes before the loosening problem was caught. These nuts came loose even when installed with the correct torque because the treads were oversized. If the nut spins on/off easily it should be replaced, not just re-torqued.

The later flywheel retaining nut design needed to be tightened to a very high torque level to keep it from loosening. It’s the highest-torqued fastener on the bike.

Except for these two model years, you’ll not get a loosening problem unless you’ve removed the nut for some reason. When you go to reinstall it you’ll find that without the proper tools it’s VERY difficult to immobilize the crank (which is necessary to reach the high torque) and many shops/owners don’t understand how critical this is. The use of this kind of nut in this particular application is on the envelope of fastener design.

The two jam nuts on the 888 aren’t critical in their torque requirements. However, some owners have decided to replace the single Ducati nut with the two jam nut design offered by Nichols.

Nichols Manufacturing, Incorporated | Welcome

A couple adventurous owners have tried Nord-Lock washers with the stock nut.

Maximum security for bolted joints -Home - Nord-Lock **

The point I’m trying to make is that if you don’t have a 1999 or 2000 model year bike, and you haven’t touched the flywheel nut, don’t worry about it coming loose.
 
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