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Discussion Starter #1
First time refitting the plate pack. The OEM pack was 50.88mm total and the Barnett pack is 51.03mm. Obviously, all the plates must be used. The depth of the inner driven hub is just over 45mm, consequently, the last driven plate and the last driver plate do not fit on the hub. What's the trick for getting the pressure plate to spin into place? Without the last two plates, I can see the proper position of the PP as it slides into and over the center of the hub as the plates wear. It appears that all the plates must fit onto the hub or the pp will not seat properly? I have pics of the assenbly before I took it apart so I know how the PP should fit. What am I missing here? The inner hub is only 45mm and the plate pack is 51mm, this is where I'm confused. I have the service manual and there is nothing about this in there, as if all the plates should fit on the inner hub.
 

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First time refitting the plate pack. The OEM pack was 50.88mm total and the Barnett pack is 51.03mm. Obviously, all the plates must be used. The depth of the inner driven hub is just over 45mm, consequently, the last driven plate and the last driver plate do not fit on the hub. What's the trick for getting the pressure plate to spin into place? Without the last two plates, I can see the proper position of the PP as it slides into and over the center of the hub as the plates wear. It appears that all the plates must fit onto the hub or the pp will not seat properly? I have pics of the assenbly before I took it apart so I know how the PP should fit. What am I missing here? The inner hub is only 45mm and the plate pack is 51mm, this is where I'm confused. I have the service manual and there is nothing about this in there, as if all the plates should fit on the inner hub.
Hmmm...clutch stack height should be 53.5 +- 1.2....but maybe your just measuring the plates not the shims? Be sure you have them in the right sequence...then it's a matter of orientation to get the pressure plate all the way down...try it without the springs and see how that fits...then put in the springs and lean into it
 

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Are you sure you took all the old plates out. You have the wavy plate on a Barnett that adds a little height until compressed during assembly, but still, the whole clutch pack should fit on the hub, at least when you start tightening the springs down. If the correct stack height is 53.5 and yours is only 51 I’m not understanding why it shouldn’t fit on the hub unless you accidentally left an old plate or two in there. I‘m familiar with dry clutches, and motorcycle clutches in general, but have not done an 821 clutch.
 

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Discussion Starter #4
Hmmm...clutch stack height should be 53.5 +- 1.2....but maybe your just measuring the plates not the shims? Be sure you have them in the right sequence...then it's a matter of orientation to get the pressure plate all the way down...try it without the springs and see how that fits...then put in the springs and lean into it
Thanks for the reply! If I "just" need to start cranking down the springs to compress the stack from 51 to 45 mm then so be it. This would imply that I should be able to compress the stack outside the huib as well. This is what I'll try today, see if the plates compress under load.....they MUST, because I took 51mm out of that hub, they MUST go back on, lol.
 

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Discussion Starter #5
Are you sure you took all the old plates out. You have the wavy plate on a Barnett that adds a little height until compressed during assembly, but still, the whole clutch pack should fit on the hub, at least when you start tightening the springs down. If the correct stack height is 53.5 and yours is only 51 I’m not understanding why it shouldn’t fit on the hub unless you accidentally left an old plate or two in there. I‘m familiar with dry clutches, and motorcycle clutches in general, but have not done an 821 clutch.
Thanks for the reply Duc96cr, yeah, all the plates out. I'm going to try and compress the stack outside the hub to confirm they can.....MUST, compress to 45mm, cuz, they MUST all fit on the hub. I'll let you know how it goes.
 

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Discussion Starter #6
Hmmm...clutch stack height should be 53.5 +- 1.2....but maybe your just measuring the plates not the shims? Be sure you have them in the right sequence...then it's a matter of orientation to get the pressure plate all the way down...try it without the springs and see how that fits...then put in the springs and lean into it
Solved......all of the plates do not fit on the hub...there is ONE driven plate that is different and fits on the PP not the hub.
 

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Discussion Starter #8
Double check your stack orientation...just to be sure...
Went on like a charm, to the eye it's tough to notice the one disc is different, but logic said there 's no way 51mm fits on 45mm. I hung the driven plates on a metal ruler and looked down the middle and noticed one not in line with the others, bam, that was it. It somehow got moved to position #2 in the stack instead of #1....I was so close, LOL.
 

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Good to know. We always appreciate hearing the end of the story. It’s sometimes like reading a mystery and finding the last chapter is missing.
 

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Good to know. We always appreciate hearing the end of the story. It’s sometimes like reading a mystery and finding the last chapter is missing.
Glad this was a happy ending, lol. It did not make sense that the hub and the total stack were so different, alas, "one of these is not like the others"........the difference is hard to spot by eye and the service manual makes no mention of one disc being different. Live & Learn!
 
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