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Discussion Starter · #1 ·
On my 2000 ST2, I had the good ole fashion squawking clutch (As you slipped the clutch from a start, it sounded like a chair being dragged across a hardwood floor). I read up on the lithium grease trick last summer and figured I would give it a try. For a while it worked great. No more squawking. Then at the beginning of this year, the clutch started sticking on me. I would pull in the clutch and then half a second later the disks would finally separate and disconnect the rear wheel from the transmission. I pulled the clutch apart and several plates were sticking together (one clump of four plates came out of the basket together and took some effort to separate). With a liberal dose of brake cleaner on all the disks, I cleaned it up as best I could and put it back together. The bike ran good again and I only had the slightest hint of a squawk.
The the squawking got louder...
... and more present...
... and then it was EVERY time that I started from a stop and every time that I rode the clutch.
... and then it started slipping.

SO, I pulled the clutch back apart today. All the fiber disks look to be in good shape (My digital calipers have dead batteries so I haven't been able to measure them yet), but it is the metal disks that I am concerned about. They are very dark and very shiny. Almost mirror smooth. Have I fried these disks, or can they be glaze busted? Or do they need to be?

Pics to come...
 

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Discussion Starter · #2 · (Edited)
The dark discs:

I did my best to capture the glare from the shine on the metal.

All measurements are in inches. I've done my best to convert to mm.

Fiber disks all read around the same thickness; 1/8" or 3.1mm:


All springs are within a tight variation of 1.5" or 38mm:


Total Stack Height is also right about 38mm:


Do any of these numbers look alarming?
 

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I’ve had good luck removing glaze from brake rotors and metal clutch plates with a vibratory sander and 60-80 grit paper. Slide all the plates in and out of the basket to find any points where things may not slide freely. Basket wear should be smoothed out . What brand clutch is it ? I’m unfamiliar with the plates making noise. I use Barnett. Remeasure the stack height when you get a battery, most issues with slipping or dragging can be traced to stack height. Verify all your plates are flat, except you might have a wavy plate in there that obviously won’t be flat.
 

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Discussion Starter · #4 · (Edited)
With a new battery, I've got much better measurements.
My springs measure at :
38.17
38.10
37.90
37.93
37.98
39.08

The friction plates measure at:
3.30
3.29
3.28
(center plate) 3.38
3.26
3.34
3.25

I have a total stack height of 38.15 and no warped discs (none that I could obviously make out, anyway).

I marked the center friction disc as special as I know the PO replaced the pack not too long before I bought the bike. It is a three piece unit consisting of a friction disk and two steel discs (one with a Bevel):


All of the steel plates measure in at an average of 1.54 (ranging from 1.47 to 1.6) except the bottom ring which was 3.2mm. Is this a Barnett pack? Or a different aftermarket pack or an add-on that the PO did? I found an ebay auction for a similar set up calling it an anti-judder update kit. Should the three piece job be in the middle of the pack like it is or twoards the bottom of the stack?


The other thing that I have noticed, as mentioned in LT Snyder's book, is some wear in the spring seats in the pressure plate. You can see through 5 out of the six seats:


The one pictures is the worst and covers, maybe, 1/8th of the seat. Just looks like poor casting design to me, but is this anything I should worry about? LT says not to worry until it covers 1/4 of the seat area.

So, in general, all the specs looks half way near decent, right? So A.) Why was it slipping? B.) If I just glaze bust the discs, should I be good to put it back together and ride the rest of the season? Or should I park it now and order up some new parts?
 

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A friend once said he had his steel plates lightly bead blasted but was on a wet clutch set up and worked great. I would think they'd work great here also.
Also if I remember correctly, my stock pressure plate on my 03 came with plastic insert cups I'll call them.


Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 

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You never stated how many miles were on your clutch?
I just ordered a new one, my current clutch has like 30,000 miles on it with an open cover. Water is not a friend here. Do you have the adjustment screws on your clutch lever? Make sure it's not screwed in too much but don't believe you would have one on your model.
Make sure there's nothing foreign in the pressure plate bearing hole which would mess up things, doesn't take much as your finding out.
Play around with it, get some extra steel plates and just try to thicken your pack a few mm. also.
Ordered my Barnett kit from Gotham for 189 w/free shipping.
Good luck

Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 

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Use a flat surface, like a pane of glass, lay some 100 or 120 grit sandpaper on it and completely deglaze all the steels. Maybe scuff the frictions a little too. The holes in the pressure plate have been there on every OEM plate I've had my hands on. If the stack height is correct and the friction tabs aren't beat to death, no need to replace it. Not sure about that odd center friction arrangement. Haven't seen one like that before. Maybe find out who makes it and contact them to be sure you are putting it together correctly.
 

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In your third pic from 8:12 yesterday the clutch plate appears to have damage. They should be perfectly smooth. Replace that plate and any others that look that way. Once you have the correct stack height, I’d bleed the clutch again and confirm that the pressure plate is lifted enough to free the clutch.
 

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And remember that the pressure plate gets installed in ONE orientation only. There's an arrow near one of the spring cavities, and one of the towers is marked (with an indented line). They need to line-up.
 

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Recieved my new clutch today and it's the same as you have. Never seen a damper plate configuration before and they eliminated the 2 steel plates installed first with just one but twice as thick.

Here is a pic of the instructions.


Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 

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Discussion Starter · #11 ·
Excellent. That confirms I have a Barnett Clutch. Thanks for the diagram. I was starting to think the PO had hobbled some things together and possibly in the wrong order.

As for mileage, it is unknown. I would say somewhere between 2000 and 5000? That's a complete guess as the PO had mentioned that he recently replaced before selling.

In your third pic from 8:12 yesterday the clutch plate appears to have damage. They should be perfectly smooth. Replace that plate and any others that look that way. Once you have the correct stack height, I’d bleed the clutch again and confirm that the pressure plate is lifted enough to free the clutch.
That is the back of the Pressure plate. The clutch has a steel ring that sits right up against it and they both have matching marks. Since they don't move against each other, would I need to replace? Or even bother cleaning up?

 

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Discussion Starter · #12 ·
Well, the $5 fix didn't work (sanding the glaze off the discs). The squealing is gone, but not the slipping. Looks like I am ordering some parts. Keeping in mind that I have two small kids and extra cash doesn't just lie around, what do you think would be the best option here?
If the glazing is gone and it is still slipping, perhaps it is a spring issue?
Should I get a new set of plates and see how it goes?
New Discs and springs?
Or bite the bullet and get a whole new clutch assembly?
I'm looking at $50 (spring) to $500 (or more for a whole new clutch Assembly). As easy as these dry clutches are to take apart, I'd really rather not have to do it on a regular basis, you know?
 

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Don't waste your money and time on springs.
Does the pressure plate stop when clutch is disengaged and what does the clutch lever feel like in terms of feeling pressure? Alot of play or consistent pull throughout?

Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 

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Discussion Starter · #14 ·
Oops... Too late. New Barnett springs are on their way. Oh well. When they get here I'll have springs I know are good and a few spares.

I'm starting to suspect my new clutch slave has been part of the cause. I put it on this spring and may not have had it adjusted quite right. Lever action is smooth and consistent throughout the pull, but it starts to disengage almost right off the handlebar and full engagement needs the lever nearly all the way out. I've got the day off today so i'm going to play with that a bit to see if I can get it better. The way it was, there was zero freeplay (well, just a little free play, but it was all in the lever - none in the hydraulics).
 

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Do you mean master cylinder?? So it has an adjustment screw? Back it out then a couple full turns and see if that helps. The piston needs to be able to move back past a hole to allow the fluid to enter back into the reservoir. If not then the clutch isn't fully engaging.
Anyone else can chime in here if I'm wrong or not explaining this correctly.

Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 

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Discussion Starter · #16 ·
An the IDIOT of the year award goes to:
THIS GUY!
KB
02

It would not be right to say the clutch was fine (as the glazing on the plates was causing some major squawking on take offs), but the slipping was not the clutch.
It would slip and then grab. Almost always around the 5K range on the tach. In my online searching, I found many other people who had similar issues with their clutch. But it was a pretty hard slip and grab... The first time it happened it almost felt like the chain skipped a tooth. And guess what? That's exactly what happened. :mad: I thoroughly examined both sprockets on a few occasions and they are both fine, but why I never thought to check the chain tension is beyond me. Holy Crap was it loose. It took 2 1/2 turns of the adjuster bolts to get it back into spec.

I am such an idiot for ignoring such a basic thing. With over 30 years riding experience I have never let a chain get that loose before. I am an MSF RiderCoach and even teach my students about their pre-ride inspection. One would imagine that I would do it to my own bike from time to time.

...such an idiot...
 

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Live and learn.

Paul 03 ST4s, 15 675RX, 96 ZX11, 76 KZ900LTD B-1, 72 SL125
 
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