Ducati.ms - The Ultimate Ducati Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1 (Edited)
I have been trying to figure out this problem for almost a year now! My clutch was working fine. the bike was backed in to in a parking lot and fell over but continued to work after that. The clutch cover was slightly bent but I don't think it was enough to contact the clutch plates. I had been riding everyday to and from work with the bike just fine. It was after a big rain storm a couple weeks later that my clutch stoped pushing the plates out all the way to smoothly shift gears.

On my way home after the storm I noticed it was getting progressively harder to find neutral at traffic lights. Now I can't shift in to 1st because the clutch lever only pulls in about half way before stoping and the clutch plates barely move outward. I'm dying to solve this but don't know what else to do.

When I opened the clutch over a lot of water came out and the plates were stuck together so I disassembled and cleaned them and put it back according to assembly instructions, all plates are correct.

The bike went to Magic City Cycles which is now Eurocycles (Ex Orlando Ducati Dealer) for the damage estimate. They said I needed a new master cylinder to which I finally just installed today with now fix on this situation.

I don't know where to look next, can the hydraulic clutch line go bad? Anything else y'all can think of? I spoke to Motowheels thinking maybe the Oberon slave was bad but they said they've only had like 1 or 2 bad out of 10,000 units.

Details:
Barnett clutch basket & plates (have about 1k miles since installed new)
Short Pushrod
OBERON Clutch Slave Cylinder with 10mm extender installed for short push rod
New Clutch throw-out bearing
STM Clutch Push Rod Pin
Brand new OEM 98' master cylinder (got this based on Shazaam's chart to go with the Oberon slave)

Thanks!
 

·
Registered
Joined
·
31 Posts
Discussion Starter #3
I didn't bleed the master cylinder but the clutch was fine for over 1 year after installing all the new components. I have a speed bleeder on the slave and use a mighty vac and I run A LOT of fluid through since it's going to get thrown away afterwards due to having to use a new sealed container each time.

I just pulled the push rod again to check for straightness and it appears to have the slightest bend, I could only tell after rolling it on a mirror for a few minutes it's that slight. Can that cause it? I wish that was the problem but feel like that isn't it.
 

·
Registered
Joined
·
852 Posts
Assure that the pressure plate is correctly aligned with the hub. The raised arrow indicator on the pressure plate need to be adjacent to the the spring boss on the clutch hub that has a notch slot.

Also, assure that the Barnett clutch plates move smoothly. Often, they have excess friction material and adhesive both on the tabs and on the outer circumference of the plates. If necessary, clean up the tabs using a small file and reassemble.

Finally, place the transmission in neutral, pull in the lever and check the pressure plate for wobble that would indicate damaged or uneven length springs.

I didn't bleed the master cylinder but the clutch was fine for over 1 year after installing all the new components.
You might have mentioned that first ...
 

Attachments

·
Registered
Joined
·
31 Posts
Discussion Starter #6
Thanks Strega: everything is ok as you mentioned except I can't pull in the lever

xracer: I'm using the OEM lever.

UPDATE: I pulled the Oberon slave off and thought I'd see if the piston would move. The lever is still hard and the piston didn't move any. I'm assuming it is stuck with the piston "in" since I can mate the slave to the push rod without resistance, does that sound correct? If that's the case, do the hydraulic lines ever go bad? It bled fine so I don't think there is a problem with the hydraulic line but idk.
 

·
Premium Member
Joined
·
5,151 Posts
We’re getting somewhere. If it bleeds then the master is moving fluid. The slave piston must be stuck. Get a “g” clamp and see if the slave will move. It could be cocked in the bore.
 

·
Registered
Joined
·
3,950 Posts
A clutch push rod can get bent b/c the crank nut for the flywheel assembly has come loose. Even if that does occur, a bent rod should still allow the slave/clutch assembly to work as normal.

You can also adjust the item on the lever (pointy thing) that pokes into the slave master cylinder. If it is not properly adjusted, it will not allow the master to do its job and so let the slave to do anything.

Lines go bad, and they leak when they do. Crush washers go bad, and they leak when they do. (or they allow a very small amount of air into the hydraulic system over a reasonable amount of time and things get a little soft but still work)
 

·
Registered
Joined
·
3,977 Posts
has the centre nut come loose allowing the hub to move out? does the slave piston bottom out on the alt cover?

there's quite a few things that can go wrong, but they're often hard to convey in a way people understand the significance of.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #10
i don’t think the center nut is loose, doesn’t that have a high torque?

I figured i’d just go ahead and take off the slave cylinder and squeeze the clutch lever to see if the slave piston would push out all the way. It would only move about 1/8” which is how much it’s pushing out the clutch pack. I’m going to call tomorrow to get a replacement and I’ll update the thread.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #12
it doesn't matter what you think. it matters what is wrong.

how far does the piston push back into the slave?
That’s what I’m saying, it’s all the way back, i can bolt it on without any problem after squeezing the lever. It won’t come out.
 

·
Registered
Joined
·
3,950 Posts
It doesn't matter that the crank nut is torqued to a high spec. they back off and ruin things. It's not uncommon. It doesn't matter that the galley plug in the crank is torqued to spec, it can back out and ruin engines.

That the slave only presses back in a small bit means that it is only being pushed out a small bit. (air in the system) A new slave and a new master, with some exceptions, leaves you with improper bleeding of the system, or an incorrectly adjusted thingy on the lever that pokes into the master cylinder. Since you've not covered those 2 things, I suggest doing them. Maybe 5 minutes of your time if you know how to do them. 10 minutes if you do not.

Having a vacuum does not mean that the master is properly (bench) bled. I've used those things for years with results that were often worse than manual bleeds.
 

·
Registered
Joined
·
3,977 Posts
That’s what I’m saying, it’s all the way back, i can bolt it on without any problem after squeezing the lever. It won’t come out.
so if you put a rod into the hole in the slave piston where the pushrod goes and push as hard as you can, the piston will only move 1/8 from where it is if you pull the slave off the engine and pump the lever many times?
 

·
Registered
Joined
·
31 Posts
Discussion Starter #15
So too wrap this up in case anyone else ever experiences this....

I emailed Steve @ Oberon who gave me a call from the UK. We were able to go over it on the phone, unscrewed the cover to the slave and I was able to press the piston back quite a bit. Steve said to put it back together and try inserting an 8mm ball bearing (ungreased incase you need to remove it but if it works then take out the ball and grease with high temp grease then reinsert), the piston has enough room to accept this. Only thing we could think of is that the Barnett friction plates added some thickness to the stack and eventually it was too much for the push rod to move.

What was actually happening is the piston was almost all the way out and could only move about 1/8 of an inch before hitting the screw on cover to the slave. Once the cover was taken off I could easily squeeze the leaver and extend the piston out.

Hope that helps anyone else should you end up reading this thread in the future.
 

·
Registered
Joined
·
852 Posts
Short Pushrod
OBERON Clutch Slave Cylinder with 10mm extender installed for short push rod
Your first post said that a 10 mm spacer was installed to accommodate the shorter pushrod (used on 2000 and earlier bikes), but your more recent post said that adding an 8 mm spacer fixed the problem.

So, either you finally used a 10 mm spacer and added an additional an 8 mm spacer — or the 10 mm wasn't installed as you initially stated.

Which is it?.

Missing the 10 mm spacer, the cause of your problem was obvious.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #17
Your first post said that a 10 mm spacer was installed to accommodate the shorter pushrod (used on 2000 and earlier bikes), but your more recent post said that adding an 8 mm spacer fixed the problem.

So, either you finally used a 10 mm spacer and added an additional an 8 mm spacer — or the 10 mm wasn't installed as you initially stated.

Which is it?.

Good thought, to clarify I am using the 10mm spacer that comes with the Oberon slave to accommodate the short pushrod and in addition to that I am using an 8mm ball bearing for a total of 18mm.
 

·
Registered
Joined
·
5,149 Posts
has the centre nut come loose allowing the hub to move out?
Not necessarily loose but on my 916 the 'petal' shaped washer on the clutch hub actually 'ate' itself into the hub - it was virtually flush with the surface of the hub, meaning that although the nut was tight, the hub moved out by the thickness of the washer (around 2mm) meaning that the clutch didn't clear as much as it should although it was still working fine.

The first sign was the spring retainers rubbing on the inside of the clutch cover but you probably wouldn't notice with a stock cover as there is more clearance inside than my open alloy, plus of course you can't see it.

May not be this but easy enough to check...
 
1 - 19 of 19 Posts
Top