Clutch servicing

I have 30K+ on my 900SSie now and I've noticed significant clutch slippage in the last few rides. At the 24K service the technician mentioned the clutch could be ready for some attention soon, he cleaned it for me though. Not sure if he just removed dust or what.. but it was okay for the next few thousand miles.

Now I'm thinking what to do - is it common to need to replace the clutch plates at this sort of interval? If so, what parts should I be replacing. I want something that will last a while... and will survive the attentions of my clumsy oafish shifting foot.

Anyone here done this work themselves?

i'm impressed that your clutch lasted this long.
it's very easy to replace the disks/plates. i'd recommend looking at a barnett stack as a less expensive and very good alternative to OEM. check out motowheels.com or ca-cycleworks.com for vendor options aside from your local dealer.
if you only need to change the clutch stack (as opposed to the basket and/or drum in addition), it should run you about $150 for the clutch pack which is very easy to install yourself. unbolt the clutch cover from the right side of the motor, unscrew the 6 bolts that retain the clutch springs, slip the clutch pressure plate off, slip out all the disks/plates from the drum, and install the new pack. note the document included with the stack for proper stacking order. reinstall the parts you removed and away you go.
while not complete, here's some pics on dissassembling the clutch. note this page is for a full clutch kit removal which isn't the extent you have to go to for this:
http://www.ducatipipemod.com/s4/mods/clutch/

might want to order a clutch throw out bearing ($9) just in case your current bearing has had it. Its the beaing on the back of the clutch pressure plate.

Brilliant.

Thanks for the information... this is exactly what I needed to know.

Actually, I think I've been riding for a while with a degraded clutch but it's worsened so gradually that it didn't really click until now.

Thanks for the link - I noticed that both Motowheels and CA-Cycleworks supply the Barnet aluminum clutch plates - do the aluminum plates wear quicker than the stock ones?

yes, the aluminum ones wear quicker, but they're lighter and not quite as loud which is nice.
if you really want to go for the gusto, see if you can track down the aluminum basket from a 999 used on eBay or in the classifieds here. they're tons lighter than the stock one and won't beat up on the plates as much as the stock steel one. shouldn't be too pricey used (since so many 999 owners pimp out with complete kits or slipper clutches) and is pretty easy to install if you've got an impact driver and torque wrench.

http://www.rebelpacket.net/bet....html



Takin' 'em out isnt hard at all. If you cant get to the ones in the way back, just use a screwdriver to pull on the tangs that stick up.

Strati and Alex - those pages make it seem so simple, all my concerns have gone now. Great resources.
Just have to figure out how to get the budget approval now!! :-) Thankfully, not too expensive though!

Jager, thanks for the tip - I'll order the bearing also just to be safe.

Thanks guys.

Oh yea! Good point about the throwout bearing!
Forgot, make sure to check to the clutch pushrod for any wear. As chris kelley put it "If you see what looks like machining grooves" then it needs to be replaced.

As far as replacing the bearing, just throw it in the freezer overnight, and put the pressure plate in the oven at 350 for 10 minutes. It'll almost slide right in. Just use a socket the size of the outer race, as a bearing driver. Works fine.

Any advice will be welcomed...

I've got my new Barnett clutch plate kit now and the pamphlet they enclosed prescribes a different sequence of plates from what is shown in the Ducati and Haynes manuals. Basically the curved plate is positioned in the middle of the pack in the Barnett instructions but near the bottom of the pack in the Ducati and Haynes manuals..

DP=Driven Plate
FP=Friction Plate
CP=Curved Plate
Barnett:-
DP DP FP DP FP DP FP *CP* FP DP FP DP FP DP FP DP
Ducati/Haynes:-
DP DP FP *CP* FP DP FP DP FP DP FP DP FP DP FP DP

As this is NOT the OEM set should I follow the Barnett directions?

I don't think it matters a whole helluva lot, so long as it's in there somewhere. I followed the Barnett instructions when I did mine, partly because it was the only reference I had at the time, so it really didn't matter. If you follow their instructions you will be fine. I haven't had any problems, and I've never heard of problems due to incorrect placement of the curved plate, but I don't get out much.

Direct from Jon Nichols

Aluminum Clutch Basket and Dry Flex Clutch installations:

If you have purchased both a basket and a clutch, the clutch plates have been installed inside the basket in the order they should be installed. In other words, they are pre-stacked. If you red the Barnett instructions you will notice they mention a "curved" plate. It is stacked as it should be. The only difference in the way we stack the plates is that we place two steel plates at the very outside of the stack rather than at the inside. We do this for one reason: It moves the entire stack closer on the center hub allowing more clearance between the most outside friction plate and the steel ring of the basket. This change has never caused andy problems. You will also notice that the outside edge of the last friction plate has been radiused for clarence with the steel ring of the basket. Please make sure the radiused side faces out when you assemble the stack. If you have purchased a Barnett clutch elsewhere or are installing a used Barnett clutch, you must radius the edges of the tabs of the outer most friction plate. If you try to place a friction plate into the steel retaining ring, you will notice it will not fit. Please take the ten minutes necessary to make this alternation. When the friction plate will set inside the steel ring and rotate, you have accomplished the task. Please contact us if you have any questions about this.

When you remove the stock basket please make sure you clean all the old Loktite from the 8mm bolts before you attach the new basket. Make sure you use 272 Loktite when re-installing the 8m bolts and torque them to 26 to 28 foot lbs. Do not over tighten the 8mm bolts or you may damage the aluminium basket. Do not use an excessive amount of Loktite as this can cause problems with the large seal in the clutch housing.

When you install the four small button head screws make sure you do not over tighten them. It is equally important that you use an allen wrench which is in vary good condition or you can damage the heads of the screws. Do not run the engine without the steel ring installed. The ring prevents the open end of the basket from growing in diameter at high RPMs. Use RTV or a small dab of Super Glue on the head of the screw to secure it. Do not use Loktite.

Thank you for purchasing our product.

-- Jon Nichols

Thanks BlueSS, I'll go with the Barnett sequence then.

CalifBlue, thanks for posting that but I got only the plates, not the clutch basket, and they are not pre-sorted into sequence. Where your post says "The only difference in the way we stack the plates is that we place two steel plates at the very outside of the stack rather than at the inside." - this is not reflected in their directions provided with the plates so I guess the directions must apply to the sequence when fitting to the OEM clutch basket.

A guy on another site said "The curve plate is set more torwards the middle now because there was a wear problem under heavy clutch slippage."

My next issue is - when I took the pressure plate off, the pushrod slipped out with it. I then pulled it out of the bearing and I slipped it back and it seems fine. The new plates went in without any problems. The rod was in decent shape and the clutch seems to actuate correctly. Not road tested yet though.

Am I fooling myself? Is this something that should NOT happen?

Also, the curved plate - am I correct in describing it as 'not very curved'... or 'barely curved'?

You are correct in that it is barely, if at all, curved. Without the dot they put on it at the factory, I don't think I could tell which one it is if my plates got mixed up.

As far as the pushrod goes, mine comes out every time I pull my pressure plate off. There's nothing wrong with that I don't think. As long as when you have everything back together it operates properly, you're good to go!

So I'm out riding today for the first time this season, and my clutch is slipping really bad. It does it under hard accelleration and when leaving from a stoplight. If I let it sit for a while, It works good, but it slowly fades away. So do I need new plates? I rebuilt the slave over the winter, and wonder if there could be something wrong with it that is causing this? Any reccomendations? Thanks...

Brennan

A couple of things come to mind, only because I dealt with this a while back and it ended up being the last thing I would have thought of. It could very well be worn out plates, depending on mileage and riding style. That's easy enough to check, just take it apart and inspect the plates. Do you have any oil leaks, particularly around the clutch? Oil dripping onto the plates can also cause slipping. Also, any sort of decreased pressure on the plates can lead to slipping, so make sure all the springs are there and snugged down. This one is less likely as there are a fair amount of folks riding with as few as three springs and report no slipping.

Does it slip when it's cold, or only when the bike warms up. The reason that I ask is that if you have any air in the clutch line, as the bike warms up the air will expand and have the effect of pulling in the clutch lever slightly relieving pressure on the plates and causing slippage. If you rebuilt the slave and you're only having slippage when the bike is warmed up, chances are you have air in the line. Try bleeding the line and see if it goes away. One thing that can make the process much easier is to install a banjo bleeder up on the master cylinder. They don't come with one from the factory and air tends to collect at the connection between the master cylinder and the clutch line due to the fact that it's the high point in the system. If you throw a banjo on there you can bleed it from the high point, lessening the chance that you'll get an air bubble.

I went through all this after a left hand low side which hit the left bar so hard it broke the clutch lever clean off around my hand. When I got it all put back together, I replaced the lever and I kept having slippage when the bike got warm. I replaced things one by one, starting with the least expensive part first and working my way up. After replacing everything but the master cylinder, I finally broke down and asked the last guy in town (a mean SOB of an old race mechanic who I avoided whenever possible). I happened to catch him on a good day and he very kindly explained to me that the Brembo MC's have valves in them that if the lever is ever compressed incredibly rapidly (as in a low side) these valves essentially get flipped around backwards and each time you squeeze the lever thereafter it sucks air into the line. Unless you've done the same, I think you're problem likely lies in the rebuilt slave and you probably didn't get all the air out. So my MC explanation was probably a waste of your time, but maybe someone else will have this problem some day and save themselves from replacing their entire clutch in the future.

Actually, I was in a lowside on that side, and this was my first real ride since I replaced the lever and the slave. I did bleed it with a mightyvac, and then used the banjo bolt as a bleeder, i.e. pulled the lever and loosened the bolt and retightened it then letting the lever back out. I also have clear hoses from the mc to the resevoir, so I know there is no air in there. Does this narrow anything down?

If you've eliminated plate wear as a source of your problems, then you might very well be in the same boat that I was in. The one thing that you forgot to mention was whether the slipping happens when the bike is cold, hot, or all the time. This might help narrow it down as it can help to tell whether it's air in the line or bad plates.

Well, I didn't correlate it to engine temp, but if I used the clutch over and over again, say in a row of stoplights, it got considerable worse each time. Then I parked it for 30 minutes or so, and it took off like a champ. So maybe I should bleed it again...

Yeah, I would try bleeding it again and see what happens. One thing to try is after it starts acting up ride it right home and bleed it. What you might notice is that if there is air in the line, when you crack open the banjo without pumping the clutch, it will spurt out due to the increased pressure from the expanded gas. That's what I found at least. But do make sure you check the plates as well, although it has been my experience that the plates get "grabbier" at higher temps, and that if it were the plates going bad then you would see slipping at cold temps and it would go away as the plates heated up from use.

Honestly, it sounds like you have air in the line. It might be due to a bad MC, but it could also just be that the bleeding didn't get all the air out. I've found that these hydraulic lines can be a pain in the ass to get all the air out and that even the best attempts can leave a tiny bubble in the line. But try bleeding it a couple more times and see if it goes away, check the plates, and if you're still having the problem it might very well be a bad MC. The guy who explained the problem to me said it happened all the time to racers he worked with and that it can happen much easier than you think. One last question, when you low sided, did you notice any clutch fluid on the inside of your fairing around where the slave cylinder? I remember seeing some after my low side and didn't really pay much attention to it at the time. Later I realized that the clutch lever had been pushed so hard that it forced fluid around the seals in the slave cylinder and onto the fairing. Kind of an aside, but I'm curious. Anyways, hope this helps.