Horrific Grinding Noise On Downshifts - Ducati Monster Forums: Ducati Monster Motorcycle Forum
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post #1 of 2 (permalink) Old 10-31-2018, 03:20 AM Thread Starter
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Horrific Grinding Noise On Downshifts

Hello All!

I get a truly terrible "chsshhh" noise when downshifting (usually 3rd to 2nd or 2nd to 1st) on my 2004 S4R (with the 996 engine). The noise goes away instantly when I let the clutch out a little bit.

I have replaced the shift lever return spring with the "69924492A" kit. (https://www.ducatiomaha.com/products/69924492a)

I inspected everything I could think of inside the left side of the engine.

I must have changed the oil at least three times at this point. I use Motul 7100 10W-40 with the K&N Filter.

I've bled the clutch.

I've disassembled the clutch twice... once down to the drum... and once down to the basket. Both times inspecting every surface.

I also get more false neutrals than you could imagine... It's kinda insane how many I get unless I stomp on the lever.

What could I possibly be missing... The bike only has 5400 miles on it...

Thanks in advance!
-Christian

Last edited by ChristianN; 10-31-2018 at 03:23 AM.
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post #2 of 2 (permalink) Old 11-09-2018, 06:37 PM
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Join Date: Feb 2010
Location: Springfield, MA
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Hello Christian,
Since you've checked everything on both sides, I think it's a problem with the gears and shift forks.
If the fork or forks that control those gears are bent or sufficiently worn, you might have a case of insufficient lateral engagement of the "dogs" on the sides of the gears. This leads to rounding of the edges of the dogs which causes the dogs to ramp out of engagement and skip over each other thus making that terrible noise.
Unknowingly resting ones foot on the shift lever could place a constant side load on the shift fork wearing it to be too thin and become loose in the fork groove on the gear. Just one possible cause.
Hate to say it, but, me thinks you have to split the cases and have a look.
Go to YouTube and find Kevin Cameron How a motorcycle gearbox works (https://youtu.be/6XZqnkhgFBY) and what causes poor shifting (https://youtu.be/6XZqnkhgFBY). These will give you a better understanding if you don't already know these things.
Hope this helps .... Leon
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