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Discussion Starter · #1 ·
Hi All,

My name is Kenny from Toronto Ontario. Im new to the forum and new to ducati ownership. I recently bought a 17,000 km 1996 900SS. It sat for 8 years before I got it. I did a bunch of things to get it running and its now running well. Upon first road test I quickly discovered a new problem. Some very weird shutter and chatter noise happening when in all gears. The engine revs smooth and free when in neutral. On and rear stand, when I pull in the clutch, shift into gear (any) and slowly let the clutch out, the noise occurs. I removed the chain and ran the engine through all 6 gears but did not hear any noise. So at first I thought it could have been the rear wheel. I inspected the rear bearings and cush rubbers and the cush was in bad shape. So I replaced both bearings and cush rubbers. Installed a new chain and re installed the rear wheel. It still made the noise. Upon closer inspection it seems the noise is coming more from the transmission/clutch area. Even though I removed the chain and ran it through the gears and it didnt make the chatter noise, It must be something that only makes the noise when under load. That is why I now suspect the transmission. If anyone has any insight into this problem, please let me know.

I have a video of the problem on vimeo

Ducati900SS-Chatter-2 on Vimeo

Just a small Recap:
-Makes no noise when in neutral - clutch pulled in or not
-Makes no noise when in gear and clutch pulled in
-Makes noise when in gear and you let the clutch out
-The noise shakes the bike like a shutter and feels like resistance.
-Clutch pack, basket, pressure plate, springs and bolts are all brand new Barnett.
-Chain is brand new


Thanks ahead of time. And I still have no pics really of the bike. Just one of when I had it apart in my parking garage to clean the carbs.

Kenny
 

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Its difficult to diagnose problems like these running the wheel on a paddock stand but it sounds like a common dry clutch problem typically referred to a juddering. Where the clutch plates slips/grips as the clutch is released. Normally it occurs only in first gear as you release the lever which is why I'm a little confused when you state it occurs in all gears? First insure the rear wheel spins somewhat freely without binding. Lift the rear wheel on the stand put the bike in neutral and spin the wheel by hand, it should spin without much resistance and without noticeable stiff spots. Do the same thing with the bike in gear with the clutch pulled in. You should hear some slight dragging of the clutch plates as the wheel is spun, you'll probably notice a little higher force to spin the wheel. If all seems ok suspect the clutch is simply juddering. Some people have reported good success by greasing the clutch frictions with lithium grease. Search here or other forums for the details.
 

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Are you lugging the engine? Keep it above 3000 in any of the gears and I'll bet the noise is gone. Let us know.
 

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Discussion Starter · #4 ·
Thanks for the replies.

Yes it deinitely occurs in all 6 gears on the paddock stand. Can't get up enough speed while riding to get through all the gears. The bike feels dangerous to ride. But I did apply some rear brake on the stand to see if it still made the noise, and does.

I'll search around for topics on greasing the plates. That may be my next step. I have spun the rear wheel on the stand in 'N' and all seems good and smooth. I'll try on the stand, in gear but the clutch pulled in and spinning the wheel by hand and see if I notice anything but when I did that same action to set the belt timing for the belt change, the rotation felt smooth. But I did have the plugs out.

I'm really itching to ride this bike.
 

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Discussion Starter · #6 ·
No to all 3. I've double and triple checked that the clutch was installed right and torqued to specs. I'm almost certain it's transmission but I have no clue where to go from here. Maybe a dealer will be needed to help diagnose. I'm lost.
 

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Unfortunately it is sounding like you may have a damaged gearbox component.

This is a biggie, if it is the case, as the engine needs to be totally dismantled to repair.

I replaced sixth gears once on a 900SS about this age. That bike was doing a long commute between rural towns in 6th gear with the previous owner, and wore the gears out.

If these are run with a low oil level, the 6th gear builds up a lot of heat on long runs.

In a perverse way, a gearbox problem can stem from worn piston rings, which tend to lower the oil level over time.

Get an expert opinion on the sound. You need someone with loads of experience to actually ride the bike and give you a verdict.

I hope it's not the gearbox, as parts are getting difficult to find. I can't even get a piston for my 1098, so I don't know how you'll go if you do need gearbox parts for a bike of that age.

:(
 

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Just another thought. Sometimes when gears are losing their hard-facing, they are noisy in all other ratios, and go quiet when in the affected gear.

I realise you are reluctant to ride it, but if you can get it into sixth, and the noise reduces, then there's your answer.

Not easy to hear anything in sixth though..

Maybe a dealer with a dyno might be worth a try, so they can hear it through all the ratios.
 

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Discussion Starter · #9 ·
Thanks for the reply pat. I think your right about the gear box issues. Every time I go back and inspect something else for the noise, that leads me to think more and more that it's a gear box issue. And by the sounds of things, rebuilds won't be easy on this bike. Finding parts anyways. Looks like I wasted money on this one. Ughh. Dealer may be my next step to diagnose the issue.
 

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meeeh.....me think its a clearance issue,clutch stack height precisely.

That basket not turning with engine running leads me to that conclusion...same goes on my 1098 when the plates are really worn.
 

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Hi Kenny just as a thought have you added an additional plate and changed the overall stack height of the plates? Have you thought of trying the old plates back in the bike?
 

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Discussion Starter · #13 ·
Hi Kenny just as a thought have you added an additional plate and changed the overall stack height of the plates? Have you thought of trying the old plates back in the bike?
No I havnt tried changing stack height. I can't use the old plates as I welded them together to make clutch basket and hub removal tools. Kinda screwed on trying the old plates. :(
 
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