Author Topic: Need a little advice on clutch pack assembly  (Read 176 times)

mmulzer

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Need a little advice on clutch pack assembly
« on: May 08, 2020, 01:19:16 am »
Good morning,

I have a 2012 Raider which the clutch went out at 900 miles.  Yamaha insisted it was a wear item until the mechanic found a hole in the sidewall of the clutch slave cylinder (clutch release cylinder) which was catching the piston and stopping it from fully seating thus not allowing the clutch to fully engage (this was from the factory).  He fixed that and replaced the discs and plates.  Now at 13,000 miles, it has been slipping again when I go to pass a car (4th gear, 55-65mph).  I have put thousands of miles on my old KZ400, Nighthawk, and never had any clutch issues so this one is really frustrating me.  It's that or I'm spinning the rim on the tire but I don't think that's the case.  Last fall I put the Barnet springs hoping that would provide more life to the current clutch.  The only test drive I was able to do was in sleet at 1 am so it really wasn't much of a test before winter.  This spring I finally was about to get out on the country roads and test the clutch.  The first time out it was slipping.  I then bled the hydraulic clutch system but really didn't see much for air bubbles.  The mechanic recommended I do this because he said the hydraulic fluid was probably gumming up.  It was nice and clear, no signs of any gumming or contamination.  The second time out it did not slip once.  The last time out it was slipping again consistently around 55-60 when I cracked the throttle. 

This evening I put in the Barnett clutch kit.  I was very careful to pay attention to how it came apart and then how I put it back together.  After putting everything back together and torquing everything as specified I was looking at the attached image of the clutch assembly.  As I was thinking about the assembly I couldn't remember if I put 15 (clutch damper spring) on the left or on the right of  14 (friction plate 3) or if the clutch damper spring just slides inside of the friction plate anyway so it doesn't matter.  Any thoughts on this would be greatly appreciated.  As it's after midnight and going to be in the 30's here tonight I am not planning on taking it out until Saturday.  I did put it in gear on the lift and the clutch seems to be working ok (I also pulled in the clutch and released it a few times while it was visible and it seemed to be moving as expected.  There was what seemed like some parasitic drag on it and the rear tire spins in gear but if I put some pressure on the brake it stops.  I can't tell how much it's pulling until I get it on the ground. 

Really I'm just looking for confirmation on whether the clutch damper spring could be in wrong and any other things I should be looking at if it still slips?  I really don't want to tear into the clutch release cylinder but if it slips again, I think this is where the issue would have to be, or the tolerances on a slightly worn clutch vs the limit on the return position of the clutch spring damper are wrong. 

The other part that is confusing me is that most of the comments on here with regard to a clutch slipping show blueing on the plates.  As you can see in the attachment there is no blueing whatsoever on these plates.  I guess it's possible that the frictions are just worn past their limit but I don't have a good caliper at home to check this and can't get into work to borrow theirs until the end of the month (current projection).  Would you expect this really isn't a clutch plate/friction issue or do you think that really is where the problem was?

As a side note, that wire circlip was fun but do-able with some patience. 

Thank you for any advice, this is a great forum and I have learned a lot from it.

Mike

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    A.T.

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    Re: Need a little advice on clutch pack assembly
    « Reply #1 on: May 08, 2020, 07:19:42 am »
    Be sure the clutch reservoir isn't overfilled.  The fluid expands as it heats up and can unseat the slave cylinder.  You wouldn't be the first who has had this issue.

    mmulzer

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    Re: Need a little advice on clutch pack assembly
    « Reply #2 on: May 08, 2020, 09:15:36 am »
    Good morning AT,

    Thank you for the recommendation.  I agree that if it was overfull it would be creating problems.  I forgot to mention I had already checked that as well last riding season.

    Thank you,

    Mike