New clutch 907i.e. '91

discussions specific to the 907IE
Post Reply
Duc77
Posts: 15
Joined: Wed Jul 25, 2018 12:01 pm
model: 907 I.E.
year: 1991
Location: Spain

New clutch 907i.e. '91

Post by Duc77 »

Hi there,

It's time to replace the cluch of my baby(has nearly 60k kms). The gears are ok but it's so noisy now. What do you recomend me?(brands/n of teeth...)How can i know if i have to change the springs and the drum...And where can I buy it.

In my country is easy to find it, but i would like different opinions to compare.

Thanks a lot.

Marc.
Mc tool
paso grand pooh-bah
Posts: 1873
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: New clutch 907i.e. '91

Post by Mc tool »

Have you done the quiet clutch mod? A really good easy mod( depending on how mechanicy you are ) that shuts up the rattley clutch and all you need is one or two old friction plates
I wish I was young again............Id be heaps smarter than last time
Tamburinifan
paso grand pooh-bah
Posts: 1527
Joined: Thu Jun 21, 2007 12:00 am
model: 907 I.E.
year: 1991
Location: Gothenburg, SWEDEN

Re: New clutch 907i.e. '91

Post by Tamburinifan »

Barnett clutch pack, quiet mod, 4 springs = smooth as silk, quiet and easy.
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
Duc77
Posts: 15
Joined: Wed Jul 25, 2018 12:01 pm
model: 907 I.E.
year: 1991
Location: Spain

Re: New clutch 907i.e. '91

Post by Duc77 »

Mc tool wrote:Have you done the quiet clutch mod? A really good easy mod( depending on how mechanicy you are ) that shuts up the rattley clutch and all you need is one or two old friction plates
Have you done the quiet clutch mod? Do you refer to the special tool to move the clutch?
I don't have but i know how to do it.

Thanks for the answers
User avatar
higgy
paso grand pooh-bah
Posts: 3325
Joined: Tue Jul 29, 2008 9:50 pm
model: 907 I.E.
year: 1992
Location: Hilltown,Pennsylvania
Contact:

Re: New clutch 907i.e. '91

Post by higgy »

Search. Ducati Quiet Clutch. With your favorite search engine

Should have been posted in the documents section :phone:


here is one of many http://www.ducati-upnorth.com/forum/sho ... Clutch-Mod

you tube https://www.youtube.com/watch?v=9DU6gjBeMHk
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
User avatar
paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: New clutch 907i.e. '91

Post by paso750 »

How can i know if i have to change the springs and the drum
Couldn't find the info in the 907IE wsm but the 900SS manual states the springs should be min. 36,5mm long.
The quite clutch mod is imo not a proper fix. The clutches rattle more over time because the clearance between the outer teeth of the friction plates and the clutch basket increases. The more clearance there is, the more noise does the clutch make. As I understand the quiet clutch mod only moves the clutch discs slightly outwards so they don't run where the clutch basket is worn.
If the basket has notches it will have to be replaced. If you have to do that I'd consider going for a 48 tooth clutch instead of a standard one.
Tamburinifan
paso grand pooh-bah
Posts: 1527
Joined: Thu Jun 21, 2007 12:00 am
model: 907 I.E.
year: 1991
Location: Gothenburg, SWEDEN

Re: New clutch 907i.e. '91

Post by Tamburinifan »

I think quiet mod is not having 2 steel discs rattling against each other.
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
User avatar
higgy
paso grand pooh-bah
Posts: 3325
Joined: Tue Jul 29, 2008 9:50 pm
model: 907 I.E.
year: 1992
Location: Hilltown,Pennsylvania
Contact:

Re: New clutch 907i.e. '91

Post by higgy »

Quiet clutch has worked well on the 906 and 907 for me for years even with their well worn baskets
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
Mc tool
paso grand pooh-bah
Posts: 1873
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: New clutch 907i.e. '91

Post by Mc tool »

Yeah me too Higgy . My basket and plates were well hammered out but the quiet clutch mod shut it up . I think half the issue with this mod is that some peeps just don't understand how it works ( I am surprised G & Gert ) It's about providing a bit of friction between the hub and the basket when the clutch is disengaged. To be fair it can be a wee bit fiddly getting just the correct amount.
I wish I was young again............Id be heaps smarter than last time
User avatar
Derek
paso grand pooh-bah
Posts: 768
Joined: Thu Nov 03, 2011 10:13 am
model: 907 I.E.
year: 1994
Location: Scotland

Re: New clutch 907i.e. '91

Post by Derek »

You are right Higgy. The mod creates a friction damping effect between the drum and the basket. I did it to my ST4s with around 2,000 miles on it. The clutch last until 38,000 miles when the friction material wore out. The drum and basket showed very little wear as did the tabs on the plates.

Image

Image

I have a PDF on the mod and how to do it but can't attach it so will work out another way.
1994 907ie
2017 Supersport 939
2015 Scrambler Classic
1982 Pantah 500SL (now sold)


Scotland
User avatar
Derek
paso grand pooh-bah
Posts: 768
Joined: Thu Nov 03, 2011 10:13 am
model: 907 I.E.
year: 1994
Location: Scotland

Re: New clutch 907i.e. '91

Post by Derek »

OK. I have converted it to an .rtf so that I can cut and paste into a post. This article is with reference to an ST4 which has an alloy basket and plates but the principal is the same whether an alloy or steel clutch. I've done it to my 907 with no issues. So here you are...


A quiet Ducati clutch, the easy way!
By Nick Woods

The following modification is based on my experiences with a ‘99 ST4 clutch, initially using an OEM basket and centre/hub plus an aftermarket plate pack, and subsequently an OEM centre and Charlie Smith/Procutting clutch basket with matched Barnett plate pack. Other members of the Yahoo LiST have tried it with success, but we have not researched into whether it can be applied to every possible combination of OEM and aftermarket components. It is important, therefore, that you understand the principles before starting work. As with any modification, there are always pros and cons, so you do it at your own risk!
—————————————

Ducati’s dry clutch has good ‘feel’ and works well, its one main advantage over the wet clutches of other manufacturers being that dust from the friction linings does not contaminate the oil. Theoretically, the absence of friction-reducing oil might also make it possible to use lighter clutch springs, but no Ducati rider has ever seen evidence of that! Given there is no need to keep oil inside the unit, it can be run open to cool it and give it a racier look, but that is when its major attribute becomes really evident. It is loud!!

Not a problem when the engine is actually driving the rear wheel, a heavy knocking noise is apparent when idling in neutral, and is sufficient to be quite offensive to those of a sensitive nature. (We shall ignore riders who proclaim that ‘loud clutches save lives’, as they are confused souls…) Whether the noise is objectionable or not, that mechanical mayhem does no good to the clutch itself, such that some owners prefer to ride the bike gently as it warms up, rather than let the clutch hammer itself apart.

The noise is directly related to the dry status of the Ducati clutch, as there is no oil film to cushion necessary play in the unit. The infrequent and uneven power pulses from the beloved vee-twin also make it worse than would be the case with a four-cylinder engine, plus the Ducati is sports-orientated and does not carry a massive flywheel that would damp the pulses better.

The knocking actually comes from the clutch plate-pack rocking to and fro in the slots of the clutch basket. The closer the clearances, as with the fabled Charlie/Barnett set-up, the quieter the unit, and having alloy tabs running in alloy slots is less resonant than with the original steel on steel. However, sooner or later, the clearances will open up with normal wear, and the knocking starts…

Several commercial suppliers have hit on a method of preventing the to-and-fro fretting of the plate-pack in the basket, and the method outlined below is based on personal experience of one of them, which utilised a special plate pack mated to the OEM ST4 basket and centre. The difference with the quietening mod that follows is that it requires nothing more than the addition of a couple of junk plates, and no machining or special components at all.

Basically, it consists of incorporating the equivalent of a rotary friction damper to bind the entire clutch unit together, (centre, plate-pack and basket) when the clutch is fully engaged. It has no effect on clutch action, but there are some theoretical mechanical/wear disadvantages that probably explain why Ducati themselves have not adopted it. (There is some evidence that Ducati did utilise it at one stage of 900 production, perhaps also with the Paso, but they seem to have abandoned it subsequently).
I’ll outline the theoretical disadvantages later but, rest assured, clutches modified in this way have given many thousands of miles of trouble-free silent service.
—————————

So, a step by step procedure that can produce a quiet clutch in minutes is as follows. I assume that all home Ducati mechanics are able to gain access to the clutch and remove and replace the plate-pack correctly. For this job, there is no need to remove either the clutch centre or the basket, both of which require special tools.

Before you start, you will need to find two old friction plates, preferably of the OEM ST2/ST4 steel type, as they are stiffer than the alloy friction plates of the OEM ST4s.

1: Remove the pressure plate and springs, and take all the loose plates out, keeping them in the order of removal. Inspect the edges of the tabs
on the friction plates, and the sides of the basket slots. There, you will likely see the wear caused by the tabs slamming to-and-fro in the slots. If the slots have deep notches in them, a new basket may be needed in the near future, or smooth engagement could be compromised by the tabs sticking in the grooves. I think there is little to be gained by filing the burrs off the tab sides, as this just reduces the contact surface-area again.

2: Drop one of the old junk friction plates into the basket first, pushing it right down into the slots. As the tabs on the plate reach the radiussed ends of the slots, they will lock into the curve while pressure is applied, and cannot rattle to-and-fro. This is the first significant aspect of the mod.

3: Then add the second old tabbed friction plate.

4: Now slide the first plain steel plate onto the clutch centre and push it as far in as it will go. For the quietening mod to work, that steel plate has to contact the face of the previous friction plate before it hits the bottoms of the splines/slots on the centre. The amount by which the friction face protrudes needs only to be around 0.020”/0.5mm, and more will not be better. This dimension will likely be different with the various options of OEM and aftermarket components you might be using, and is also influenced by any wear on the front face of the clutch centre. Checking the amount of overhang will require a short straight-edge that can be laid across the friction faces adjacent to the roots of the slots in the centre.

5: Replace all the other plates as they came out, including the cone-shaped spring-plate, whose exact position and orientation does not seem to be critical. (Note that the wave-profiled spring plate in the Barnett plate-pack gives more resilience, and may be a factor in abolishing the famous ‘groan’ on take-up. Refacing your stock plates can apparently work too).

6: Disregarding the extra two plates in the bottom of the basket, your effective plate-pack thickness should only have increased by that 0.020”/0.5mm mentioned in 4 above. This should mean there will be no issues with plates coming out of the basket slots or off the centre when the clutch is disengaged, especially if your plates have seen some use.
However, you should check this before running the bike. The specified max thickness of the pack is 38.5mm, but a mm or so less is permissible.
If you have to juggle with plates, remember that different brands vary in thickness and number, and I see no problem with mixing-and-matching plates to get the right total thickness. If you find it difficult to get down to the 0.020”/0.5mm overhang, you could always reduce the thickness of the friction material on the two additional plates, but do it evenly on a flat surface to keep the outer surface square to the rest of the components. Finally, make sure that the very last plate you put in is a plain steel one for the pressure plate to contact.

7: With the clutch back together, and the springs seated and tightened carefully, test the action without the engine running:
A: Pull the clutch lever right in with one hand, and then gently rock the pressure plate with the finger-tips of your other hand. You should see that all items (pressure-plate/centre, plain plates, friction plates and basket) are free to move independently, within their limits of play.
B: Now start releasing the lever while still rocking to-and-fro. You will see the pressure-plate and all the plain and friction plates start to bind and move as one, but that unit will still rock within the slots of the basket.
C: As you let the lever out finally, you should see that the whole unit goes solid, such that the tabs will no longer rock within the basket slots. Any remaining movement is now inside the gearbox.
8: Replace the clutch cover and start the engine in neutral. Silence!!

Now test-ride the bike with caution to check that you can find neutral as easily as before. The dimensional change with this mod should be compensated by the hydraulic actuation, but there will be slightly more lost motion as the plates bed and flex a little. If you have a problem, either abandon the mod or check ways of increasing clutch lever travel by incremental adjustment of the lever screw (Caution!), bleeding the hydraulic line or bending the lever blade out.

Now to the theoretical drawbacks of this mod.

A proportion of the clutch spring end-loading is now being transferred to the basket, which means that the bearing in the back of the clutch basket mount is seeing an unfamiliar endload.

In addition, action and reaction results in loading of the alloy clutch centre against its steel retaining washer, which interface is dry. The clutch centre incorporates the cush-drive rubbers that smooth the power pulses, especially at low speed, and this loading could reduce the effectiveness of the cush mechanism and accelerate wear at this point. Personally, I can detect no difference in the feel of the power pulses before and after the mod, but there will be more wear as the centre and retainer fret against each other. Perhaps a PTFE shim at this point might be a good idea…

I feel the wear issues are genuine, but I choose to believe that they are not significant. Many Ducati riders have covered substantial mileages using one form or another of this modification without problems, and I’m sure all would agree that the silence and reduced wear on the clutch tabs and slots are well worth the risk. In any case, it will take only minutes to revert to standard, should you come to decide otherwise.

Please note that this is simply free advice from an owner/rider, and you make this mod at your own risk.

Nick Woods, Norfolk, UK, May 2006
1994 907ie
2017 Supersport 939
2015 Scrambler Classic
1982 Pantah 500SL (now sold)


Scotland
Duc77
Posts: 15
Joined: Wed Jul 25, 2018 12:01 pm
model: 907 I.E.
year: 1991
Location: Spain

Re: New clutch 907i.e. '91

Post by Duc77 »

Thanks everybody for the answers. :thumbup:

I'll try to replace in a short time cause i don't have time now.
And yes,changing the position of two plates decrease the noise, but i don't remember it. I don't mind cause i like original clutch sound.

Thanks.
Mc tool
paso grand pooh-bah
Posts: 1873
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: New clutch 907i.e. '91

Post by Mc tool »

Mine rattled like a demented school boy with a bucket of stones....but once I figured that it was harmless ,I did enjoy the reaction of bystanders when I kicked her in the guts( that's Kiwi for starting up an engine )
I wish I was young again............Id be heaps smarter than last time
User avatar
Derek
paso grand pooh-bah
Posts: 768
Joined: Thu Nov 03, 2011 10:13 am
model: 907 I.E.
year: 1994
Location: Scotland

Re: New clutch 907i.e. '91

Post by Derek »

Mc tool wrote:Mine rattled like a demented school boy with a bucket of stones....but once I figured that it was harmless ,I did enjoy the reaction of bystanders when I kicked her in the guts( that's Kiwi for starting up an engine )
But it's not harmless, it wrecks the tabs on the plates and creates notches in the drum and basket.
1994 907ie
2017 Supersport 939
2015 Scrambler Classic
1982 Pantah 500SL (now sold)


Scotland
Mc tool
paso grand pooh-bah
Posts: 1873
Joined: Wed Dec 05, 2007 12:35 am
model: 906 Paso
year: 1990
Location: Newzealand

Re: New clutch 907i.e. '91

Post by Mc tool »

Well , no more harmful than rubbing your tires to bits on the road :D ,and whilst tangs ,and to a lesser degree the basket ( if it's steel ) do take a bearing it doesn't affect reliability .........but I do know what you meant Derek. I rationalise that by saying that its expected. To be honest I didn't mind the noise and the only reason I did the quiet clutch was coz I couldn't resist the temptation to have a fiddle :)
I wish I was young again............Id be heaps smarter than last time
Post Reply