Replacing clutch plates, a pictorial

[mike-s]

I couldn't remember if anyone else had put a pictorial together of clutch plate replacement, so here we go. (Copied from my flickr account)

1) Drain the oil before taking the side cover off.

2) Remove the side cover off the crankcase, remember to double-check that you've removed all bolts before trying to persuade the side cover off.

3) Remove the clutch spring bolts

4) Remove the clutch pressure disk, exposing the clutch pack.

5) Remove the driving & driven plates from the clutch. This can get fiddly, especially if your clutch (like this one) has a metal band partly around the outside to assist with ridigity.

6) With the plates removed you can see the wear marks on the outer clutch housing. The wear marks on this clutch housing are still mild enough that they aren't going to interfere with the clutch release. You'll also note that you can see some spring wear marks on the clutch spring posts. This is quite likely possibly related to spring fatigue. The marks aren't too bad, so i made do with the existing drive plate.

7) The existing fibre plates are within spec but I replaced them anyway. Some of the metal plates have some noticeable scoring, and a couple have some bluing as well.

8) Remember that there are different clutch plates, both fibrous and metal. Refer to your motorcycle service manual for specifics relating to yours.

9) Metal plates can sometimes get bluing due to high slippage or potentially the plates drying out due to lack of use and then the bike getting a flogging.

10) There are different thickness metal plates and they need to be put into the clutch pack in a specific order. The same goes for the fibre plates. There are 2 of these 1.9-2.0mm plates in the stack.

[END PART ONE]

 

[mike-s]

[PART TWO]

11) There are different thickness metal plates and they need to be put into the clutch pack in a specific order. The same goes for the fibre plates. There are 7 of these 1.5-1.6mm plates in the stack.

12) The old fibre plates are still within spec at 2.9mm, the service limit for these is 2.5mm

13) Soak the new clutch plates in clean engine oil for a minimum of 2 hours before assembling them.

14) Remove the plates from the oil and let it drain before reassembly.

15) Plates start out at 3.1mm thick prior to use.

16) Remove any plate bluing with at least 600 sandpaper, i used 800 wet & dry paper & gave them a good clean afterwards..

17) When you replace the plates for god sake don't skimp and re-use the old springs.

18) Measuring the old & new clutch springs confirms if the old springs are still within spec. I would still replace them anyway as a new set of springs only adds about $20 to the cost. These are the old springs and due to fatigue are 2mm shorter than the new ones.

19) Measuring the old & new clutch springs confirms if the old springs are still within spec. I would still replace them anyway as a new set of springs only adds about $20 to the cost. These are the new springs and 2mm longer than the old ones.

20) The old & new springs side by side shows the difference that fatigue can make.

[END PART TWO]

 

[mike-s]

[PART THREE]

21) Clutch pack reassembled & back on the bike.

There are some little bits & peices like clutch plate arrangement, but things like that need to be addressed on a per-bike basis like i mentioned above.

n.b. If anyone is wondering why i have the gloves on. Simply put, used engine oil has been found to be a carcinogen, also tidyup is a bit easier if you wear gloves as much as possible. And yes i know nitrile gloves last longer, but i have a 100 pack of latex gloves in the garage and have been working my way through them for the past year or so.

 

[sharpy]

Good tuturial but when removing and/or replacing any bolts under pressure its advisable to do them diagionally and a bit at a time. Acess to some sort or sand blaster to do the steel plates would be ideal and those steel plates should all go in the same way they came out. There stamped out and have a flat face and a rounder face on them. Otherwise good job. Sorry im anal, lol.

 

[Nessism]

Good tuturial but when removing and/or replacing any bolts under pressure its advisable to do them diagionally and a bit at a time. Acess to some sort or sand blaster to do the steel plates would be ideal and those steel plates should all go in the same way they came out. There stamped out and have a flat face and a rounder face on them. Otherwise good job. Sorry im anal, lol.

Never noticed this before. Going to dig though the spares bin now and look for that mark since I didn't pay attention to this detail when rebuilding my 1000 engine.

 

[Dogma]

Never noticed this before. Going to dig though the spares bin now and look for that mark since I didn't pay attention to this detail when rebuilding my 1000 engine. My clutch works fine other than a little slipping when really gassing it. Wonder if this is the problem?

Ed, I think he's talking about the manufacturing process, not an identification mark. Being punched out of sheet, the plates naturally have one edge sharper than the other.

I don't know how much it matters, but I suppose you'd want the rounded edge facing inward, as that's the direction the stack will most likely be moving while loaded by the engine (if you never use engine braking). The other way might conceivably tend to dig into the basket. Neither edge should be sharp enough to do this, though. Maybe lower quality plates?

 

[bonanzadave]

Very nice sir. That will help many a GSer. Have Cliff add it to his webby.

The big hub nut is a weak link. Advisable to replace with a APE or upgraded nut.

 

[cowboyup3371]

Very nice set of pictures.

Question - how did you know you needed to replace them? My clutch didn't feel bad but I'm going to be taking the crankcase cover off soon anyway so maybe I'd have a look around. Is there anything else I should look for to know if I need to replace mine?

 

[sharpy]

Never noticed this before. Going to dig though the spares bin now and look for that mark since I didn't pay attention to this detail when rebuilding my 1000 engine.

Yes like Dogma said its the manufacturing process. Just something thats been mentioned by a lot of people. If you do a clutch thats never been apart you will notice there that way. Its just the old "put it back in the same way it came out" theory.

 

[mike_of_bbg]

Very nice set of pictures.

Question - how did you know you needed to replace them? My clutch didn't feel bad but I'm going to be taking the crankcase cover off soon anyway so maybe I'd have a look around. Is there anything else I should look for to know if I need to replace mine?

If your clutch slips at speed it's time. OEM clutch springs are cheap - what under $2 each? Unless abused/raced the clutch discs rarely wear out. The springs do get tired after 30 or so years. If you're going to be in there anyway...

Man I tried some EBC clutch springs in mine. They say 10% stiffer but it was WAY more than that - or maybe just stiffer + preload from being longer. In any case I thought my clutch cable would snap every time I pulled the lever. Felt about 100% stiffer. Went and bought new OEMs. Seen many with the same complaints about aftermarket springs. If you're going to go that route try replacing just 2 or 3 springs first.

I'll send you my old EBCs if you want 'em. Hardly been used

 

[mike-s]

Well I'm trying to track down a slightly unusual behavioural problem where it feels like there's a brief bit of slip and a slight thud feeling as you get on the gas, which has been getting progressively worse as time goes on.

Previously it would do it once in a blue moon and i really had to twist the throttle hard to get it to make it react like this, and not knowing which part to look at first due to the unusual symptoms. But a month later the symptoms can now be reproduced at less than 1/3rd throttle instead of the over-half throttle it took previously.

I figured i should take things logically and try and determine the cause by looking at one of the easiest to sort out candidates first, and then move onto the carbies afterwards if needed (I haven't taken her for a ride yet, and am *really* hoping this sorts the problem out as i have a big ride to do next week and little opportunity to do a test ride beforehand).

Also i had no idea if the previous owner had replaced the clutch pads or not.and figured i might as well just do it to remove it from the list of unknowns.

Also there is the possibility that one of the carbs was sticking and not opening beyond a certain point and now that i'm giving her a well deserved flogging shes starting to work past the stickiness and starting to open up the cv sliders correctly. Taking the air-filter off and taking a bit of a look is something I'm also planning on sometime over the next couple of days.

So there you go, partly troubleshooting, partly necessity.

As to the undoing the bolts in an orderly fashion, i did that, but just neglected to mention it in my write-up as i didn't want it to get too wordy. Thanks for the comments & criticism.

 

[mike-s]

Its just the old "put it back in the same way it came out" theory.

I have a copy of a suzuki service manual, nothing mentioned about putting either metal or fibre plates in facing a specific direction, only that you need to put the small number of differing plates in, in a specific order.

The springs do get tired after 30 or so years. If you're going to be in there anyway...

Being that my bike is from 1997, that's a little concerning.

Man I tried some EBC clutch springs in mine. They say 10% stiffer but it was WAY more than that - or maybe just stiffer + preload from being longer. In any case I thought my clutch cable would snap every time I pulled the lever. Felt about 100% stiffer. Went and bought new OEMs. Seen many with the same complaints about aftermarket springs. If you're going to go that route try replacing just 2 or 3 springs first.

have been warned about the "10%", will see how it goes, firstly i need to see if this annoying issue is fixed, then i can worry about getting adjustable levers, etc.

 

[Steve]

I don't know of any GS-series bikes that have different steels and different fiber plates.

Since your bike is a '97, it's obviously NOT a GS. What is it? :-k

Also, if you put your bike on the SIDE stand, you can skip step #1.

.

 

[Ranger]

The slipping at speed when you twist the throttle can be dangerous, mine slipped completely when I attempted to make a pass into oncoming traffic and upon further observation I noticed the cable wasnt adjusted right.

Did you ever check your cable to see if its new and releasing all the way? Even a little bit of tension in it @ power will cause it to slip when you wont notice so much at lower rpms.

Spring stiffness was mild for me, however my bike only has 3 springs, maybe four I forget.

Hope you figure it out.

 

[mike-s]

It's a RF900, my other bike is a GS/GSX250.

And it's quite conceivable that putting the bike on the sidestand would suffice. However as i had the bike on a rear/swingarm stand while i replaced the rear tire i just did it this way due to the "cbf" factor.

As to clutch slip, i wanted to replace it before i got that sort of behaviour as i just didn't know the health of the clutch, it was a total unknown. Also it's a hydraulic clutch, which i serviced only 10 thou km earlier.

 

[Suzuki_Don]

My experience is that I had the same problem with my 550/700 (75hp). I pulled out to pass a 4WD vehicle and when I was beside him with oncoming traffic all of a sudden there was no drive to the rear wheel. Heart immediately moved from chest cavity to throat. Luckily I throttled off and on again and I got the drive back and passed the 4WD in plenty of time. Did I mention I was going uphill at the time.

I then fitted EBC friction plates and found that the gear changes, particularly in the lower gears and moving at low speed in traffic where many gear changes are required, were very notchy and sometimes could not get the bike out of gear. I had also fitted three of the six EBC 10% extra rate springs to the pressure plate. This made the clutch extremely heavy in use. Glad I didn't put all six EBC springs in.

So I then pulled the clutch again as I couldn't ride with the bike in this condition. I measured the tabs that fit in the outer section of the clutch basket and found that they were all over 12+mm. When I measured the originals they were on average 11.8mm and I remember when fitting the fibre plates they were quite a tight fit in the basket, I had to line them up very carefully to get them to slide into the basket.

So armed with this new information I filed the new plate tabs down to 11.8mm each on the side of the tab that does not take up the drive on account that if my filing was not absolutely square the plate and tab might be bearing on a small part of the tan if you know what I mean.

So I reassembled everything with the curved side of the steel plates inwards and installed this time the six new OEM clutch springs.

And from then on it operates perfectly. No slippage at full power. Light lever pressure with OEM new springs. And good and easy gear changes.

So this is the way to go in my opinion. New fibres with correct size drive tabs and new OEM springs. Works really good unless you have a really hotted motor like CHEF.

 

[Graham]

Something that was missed in the pictorial was checking if the steel plates are warped. Lay the plates on a flat surface (like window glass) and use a feeler gauge to check distortion. 0.1mm or less is normal. Check model specs.
Warped clutch plate makes a clutch unadjustable. A clutch that drags (hard to find neutral) when pulled and slips when released (under heavy load) may have a warped plate.

 

[Suzuki_Don]

Lay the plates on a flat surface (like window glass)

1/4" thick plate glass is best.

 

[Graham]

Might wish to mention you want to use the same oil used in your bike (no friction modifiers, such as diesel motor oil).

If you use "regular car" oil to soak them, you can have problems.

Nice writeup, and thanks for sharing!

- JC

Why and how did you come to the conclusion that the type of oil that clutch plates are soaked in is going to matter, car or motorcycle?

 

[Graham]

Most "car" oil has friction modifiers which will interfere with the proper operation of the clutches. That's why we use "diesel" oil in our bikes.

Soaking the clutches in the wrong oil will contaminate them and can cause them to slip.

- JC

I did read some stuff about friction modifiers but the words are ?could interfere? not ?will interfere?. To think about it the clutches didn?t slip because of friction modifiers 30 and 40 years ago when they became poplar. Has anyone ever tested this? Could it be somebody wants to sell high priced motorcycle oil? But then again I never heard of any issues from using oil for diesels in motorcycles either. But this is not the thread for this discussion.