This seems to be a topic that comes up rather regularly, and it seems there are a lot of people who would like to know more about their clutch.
I'm sure we all know what a clutch does, it provides a dividing point between the engine and the transmission. It is made up of an alternating series of fiber discs, and steel plates, and a set of springs which determine how much force engages the clutch when the lever is let out. I'll give abasic rundown on how to remove your plates, inspect them for wear. (This was done on my 600rr, some of the specific numbers may be different from other bikes, but the basic process is the same for pretty much any bike)

(oh also, lol, this was done on an extra 600rr engine i've got, you can do every last bit of this with the engine still in your bike, haha, just wanted to throw that out there)

What you'll need:
3/8ths drive ratchet
3/8ths drive torque wrench (preferably one that reads under 10 lb/ft)
8mm socket (for the side cover bolts)
10mm socket (for the clutch spring/pressure plate bolts)
caliper or micrometer (to measure plate thickness)

Removal:

Take off the clutch sidecover (no ****, lol)


Remove the clutch spring bolts and springs and set them aside




Remove pressure plate, then the discs and plates, keep them in order (this is important, lol)






Inspection:

you'll want to pull out that caliper now, its time to do some measuring!
you'll need the factory specifications and service limits, which you can find online, or in a factory service manual (which i highly suggest)




As you saw in the last pic, im looking for a minimum fiber disc thickness of 2.92mm, so.... if any one of them is anything less than that, you'll want to replace all of these
(notice how i'm keeping them in order around my arm, get creative, just make sure you dont mix them up)



other things you want to check are the clutch spring free length, which can be checked with the caliper as well (should be 46.5mm, but no less than 45.2mm, replace all of them as a set), and plate warpage (set your steel plates down on a plate glass table, if any of them are warped at all, i'd replace the set.

(if your clutch was slipping, but the discs all measure up, your springs are most likely worn out and weak)


If you find that you have to replace springs, or steel plates, they go in just like the old ones came out (nice and simple huh?)
the only thing you'll have to do anything special for is the fiber discs: if those need replaceing, you'll have to soak the new ones in fresh oil, otherwise your new clutch will be grabby.

Replacement:

simply reverse the removal process, install them in order, theres 8 discs and 7 plates (oops, dont lose any!)







slap that pressure plate back on



reinstall the springs, and run the pressure plate bolts down by hand, and then get the torque wrench set to 9 lb/ft and torque those sons of bitches down!
(my torque wrench is too big, but thats about right)


[IMG]http://i3.photobucke

 

What exactly would make the clutch go bad prematurely and how much does the new clutch cost? Aren't there "performance" type clutches and are they worth it?

Sorry so many questions.....
Nice write up by the way!

 

lol the short answer as to what would make your clutch give up on you early is drag racing. but other than that, any time you use the clutch, you're wearing it down a tiny bit, slipping it from a dead stop like at a light, or stop sign wears it down (as does slipping it @ high rpm like during a drag launch lol) it all depends on how you treat it, the more time time you ride the clutch, the quicker it will wear out. clutches will last a long time under normal circumstances, but they do eventually wear out like anything else.

(when you pull the clutch lever in, the steel plates spin attatched to the inner hub of the clutch basket, while the fiber plates spin on the outer hub of the clutch basket, when you let go, the fiber discs and steel plates all press against each other to make both hubs spin together, so you can see how riding the clutch could cause wear)

depending on bike and brand, they can be somewhere between $80 and $120, sometimes more, sometimes less, depending on friction materials (kevlar, carbon fiber, organic) and the springs. for street riding, the performance clutches wont give you anything you didnt have before with the factory clutch pack, but for road and drag racing, they do make a difference.

 

Are there obvious symptoms that your bike has to let you know when the clutch needs to be changed. What's a ball park time frame for when you would need to replace your clutch?(For a non-abusive, casual rider)

 

it will become very obvious, under power with the clutch engaged, it may slip, you'll notice as you twist the throttle, the revs will climb, but you dont accelerate immediately.

a clutch pack will last a long time under casual, every-day riding. ive got 45,000 miles on the cb750 clutch that we put in when we rebuilt the bike, with no slippage so far.

 

good write up, answered some questions

 

Nice article...well done...

 

Thanks bro. Very informative.

 

We need to drain the oil prior to this correct?

 

yes, correct.

either that or tip the bike way over to the left, but it would be easier just to drain the oil beforehand.