Clutch Replacement

I've noticed a very small amount of clutch slip at high speeds - if I'm doing 70 ish on the motorway & give it a handful, it's feels like the revs rise before the speed.  Doesn't do it a low speeds or from standstill though.

Preparing for the worst, I'm thinking of doing it myself.  Bit of advice please - what kit is recommended, & do I replace the steel plates as well as the friction plates & springs?  I've read that it's recommended that the plates are soaked in oil before fitting - what's that all about?

Is it as easy as it appears - anything likely to trip me up?

Cheers

Not really my area this but being soaked in oil before fitting makes sense to me, cause my understanding is it's a wet clutch system on these bikes. Clutch slip can even happen on them if the engine oil is not the best quality or is getting old cause it shares the same oil as the engine

Crash is on the money with the oil as this is a wet clutch, the type of oil, the age of oil can both make a difference.
Remember that these bikes do not have a self adjusting clutch system in place & manual adjustment must be made as the plates wear.

Hi, I bought my 2008 C800 with 4000 miles about six months ago from a dealer. I had the exact same problem and the dealer said the clutch plates were probably slipping due to the bike being standing unused for a long period while in the showroom. Well the problem got worse and after much adjustment decided to change the clutch myself. I've never done it before but there are some great videos on you tube ( Motorcycle wet clutch replacement search ) it really is quite straight forward and I am not great at DIY.  I got the parts from Wemoto for less than £60. Clutch friction plate set, heavy duty springs and clutch cover gasket. When I got the friction plates out they were totally worn through which was surprising for a bike with low mileage.. I did soak the plates in oil overnight and all is now working great..When I took the plates to the dealer he refunded the cost of the parts..RESULT. I now have peace of mind for many years.. A job well worth doing yourself just take your time. Sorry for the long reply but hope it helps.

Good shout on getting heavy duty springs when replcing the plates.

Thanks for that.  I see that Wemoto do the friction plates for £53 & uprated springs for about a tenner - they also do the steel plates for £26 - is it worth changing them at the same time or don't they tend to wear?
Cheers

I didn't bother with the steel plates and when I examined them they were in great condition. I think they only need changing if they become warped or badly scratched. The original plates are OEM quality and you would be replacing them with aftermarket which will probably not be up to the same standard. Personally I am a bit tight and wouldn't bother forking out another 26 quid. 
If I can be of any further help just let me know.

Agreed.  

Hi Folks,

I have a similar 'occasional' clutch slipping issue on my VX. I am aware the VX has a 'slipper' clutch to help on the downshifting (stopping the back end tramping if you downshift rapidly & lose road speed/engine speed coordination). A slipper clutch on an early 90's design was really quite advanced, and one of the endearing qualities of the VX is that you forget it is shaft driven as it has none of the 'quirks' of a shafty ... other than the added weight maybe). I'm not 'au fait' as to which other Suzi 800s have the slipper clutch - but it will be identified in the Suzuki workshop manuals I don't think the chain driven VZs have a slipper clutch .... it is only likely to be found on the shaft driven models.

Anyhow ... I read up on the issue and one of the solutions is to shim the clutch springs. These can, I believe, be bought off the shelf in the states, or you can make up your own from modified washers. The thickness only needs to be about 1.0mm .... too much & you will get spring binding. I've made up a couple of different types of washer .... but as yet have not got around to stripping off the clutch casing to fit them.

I've made up a couple of different sized spacers from oversize M8 washers, with the hole drilled out to 9.5mm. this is a bit of a pain to prepare, drill & deburr the washers with simple hand tools - it would have been better if I had access to a lathe ... but I didn't ! I will have to strip the bike down to decide which washer to fit.
The cost of the washers is nominal ... the fiddling about to modify them takes awhile - & if you value your time more than money it ain't the most time affective option. I made up my spacers in several moments of spare time - just 'cos I had nowt better to do at the time - or I was waiting for someone else etc. & had a small time slot to fill.

There are 8 springs on the VX clutch ... 4 for the main clutch & 4 for the slipper clutch. I would imagine the 'slip' we feel is from the main clutch springs - so I was wondering about only shimming the 4 clutch springs so as not to alter the effect of the slipper clutch (i.e. it will kick in at the same 'back- loading' ... otherwise you might get some slight squirming of the rear end on rapid 'shut-downs' or fast deceleration going down the box). The springs are to a different spec (ever so slightly). Aftermarket - stronger - springs are usually 8 of the same .... so the same question would apply - do you change the ones on the slipper clutch.

Several other people have used this mod & it works. The issue is that once you've stripped it down it is as easy to put new parts in as it is to shim the springs..... & you have to pull everything apart to visually examine the components for wear/serviceability.

Due care is needed to check everything out to get the best results. If prolonged slipping occurs, then it may cause premature wear of the friction plates - but it they are 'within specified limits' (Thickness quoted by Suzuki) then they should be OK. But there is little point in shimming worn below the limit plates !

There could be glazing on the plates and this can be partially removed with wet & dry. I would lightly scuff any plates if I was to reuse them. (Steel & friction plates)

The use of stronger springs is a similar tactic to shimming the existing springs - it is just that new springs costs more than shims ! Either mod will give a slightly stiffer lever feel - but not to the point of making the clutch lever difficult to operate.

As mentioned above - the first point of call for clutch slip is checking the clutch adjustment ... not on the handlebars, or outer transmission casing, but the one inside the transmission casing (inside where the clutch cable goes into the engine unit. There is a screw & locknut arrangement in there that needs periodic checking & adjusting. Always check that for correct adjustment ... it does help stop the slip.

Other considerations .... what oil are you using - & is it 'bike specific oil' (i.e. designed for wet clutches). Some types of modern car oils have additives that do not work well with wet clutches and this can cause some clutch slip - I think it leads to glazing of the plates. Motorcycle oils are generally dearer than the more common of car oils, but it is because they are blended to suit wet clutches .... car oils are not - because most cars have 'dry clutches (by design !!!).
Some people believe mineral oil is better in wet clutches rather than synthetic, or semi synthetic. I would generally stick to what grade the manufacturer recommends - but have never had problems using semi synthetic, or fully synthetic oils in my bikes.

Hope that might help inform forum members of some more of the clutch issues.

I will post an update once I've fitted the spacers .... but don't hold your breath !!!!!

   Yam

What a fantastic answer!

I've done a "full" clutch adjust & I'm not even sure it's happening now - I think I'm imagining it. I reckon I'll monitor it over the season & if it gets any worse I'll change the whole lot, if it stays the same, just uprate the srings. As I say, it's fine from stand still or on hill starts.

katsd wrote:

What a fantastic answer!

   Yam is very often the man for a full inclusive response.  

Good call Yam, well explained

Hi again Dave R,

It sounds like we've got similar symptoms .... it is no 'regular' clutch slip .... like when going uphill in a high gear & opening the throttle & the revs rise greater than the road speed increase .... it just those occaisional feelings of slip.

I find when I've done the 'internal 'clutch adjustment it does not seem to do the slipping for awhile .... I usually test on a local long motorway incline in hard top gear acceleration.

When is does occur it is often 4th or 5th gear overtaking where the revs seem to rise higher than the rate of progress. This seems to be a common problem on Suzi 800s with slipper clutches .... & I don't think it is actually the fault of the slipper clutch .... but if the main clutch is only using 4 springs I could see why it might let go 'occaisionally. The slip when it occurs it not dangerous, in that it does not significantly impede your overtaking manouever .... but the feeling kind of messes with your head.
So much so that I read up on it, & I want to try the shimming option first - as it would be a cheap fix if it works.

As mentioned I have made up two sets of 8 spacers. The sets are slightly different sizes, & until I've stripped of the clutch casing I won't be able to tell which I would use. I will endeavour to get this job done soon .... & will feedback my findings as if could be helpful to a few members out there.

   Yam

Hi Folks,
I just tried to post a long message about me fitting the clutch shims - the message just got wiped as I was check reading it - pilot error !!!!!
Bottom line is - it seems to work. ..... I will retype the message (with photos) tomorrow !
  Yam

Thanks for that - let me know - cheers

Yesterday I had the opportunity to do an oil change on the ‘VX’. This also gave me the chance to take off the clutch cover & check out the clutch assembly.
As you will know I, along with Dave R & other forum members, have been suffering some clutch slip. This is not the usual clutch slip of always slipping in the top two gears when opening the throttle in a high load situation - such as going uphill from low revs, which is characterised by an initial rapid rise in revs that does not correspond to the same increase in road speed. The slip I have been experiencing is often in 4th & 5th overtaking situations, where you do get an initial rapid rise in revs that does not correspond to the same increase in road speed – BUT it does not ‘slip’ all the time like a worn clutch would.  
Anyway, I took off the clutch casing. To do this on the VX you have to loosen the offside (UK) exhaust fittings & remove the exhaust pipe from the front cylinder casting. I loosened the clamp bolt on the balance pipe & the rear silencer hanger bolt. This allows you to lower the exhaust to get access to the lower hexagon bolts at the bottom of the clutch cover. Also on the VX, I wondered if I might have to remove the rear brake pedal …. But you don’t. – if you loosen off all the bolts, you then need to tap the clutch cove to release it from the steel dowel tubes (two of). I managed with hand taps – but the workshop manual indicates a soft mallet may be needed. Once the clutch cover is free of the dowels you an almost remove it, and if you depress the brake lever there is enough ‘wiggle room’ to remove the clutch cover whilst leaving the rear brake pedal undisturbed.
On exposing the clutch basket assembly, the first thing I did was use a big red felt pen to match mark the inner clutch cover plate and the outer clutch basket. I marked one of the long webs on the clutch cover plate, and two upstands on the clutch basket, so that the marked long web sat in between the marks on the clutch basket. This is to aid reassembly because of the different jobs the 8 clutch springs do. There are two types of clutch spring, ‘Type A’ which is for the clutch, and ‘Type B’ which is for the torque back limiter (Advanced idea on a bike originating in 1991). I removed all the clutch springs, but here is a photo of the springs removed, but with one of each loose in their proper location :-




You will notice the springs actually look different, with the Type A spring having a white paint mark, but here is a photo of the spring assemblies to highlight the differences :-






The Type A spring is to the right, with the white paint flash. This has a longer 40mm bolt. The spring is marginally longer but the tube spacer is the same size for both types.
The Type B spring is to the left, with no paint marking and a more open spring with less coils. This has a shorter 35mm bolt.
Some people have claimed the bikes can come out of the factory with the Type A & B the wrong way round – but I would remain open-minded about that (But clearly worth checking).
There is a washer fitted to the bolts, this does not slide off. You could probably remove it if you held the washer in a vice & wound the bolt out. I think this is an original fitment washer and not someone else’s shim.
I made my shims from M8 stainless washers, opening the hole out to 9.5mm and de-burring both sided of the hole. These washers were about 1.0mm thick. I have placed one shim by the Type A bolt assembly. It should be fitted under the existing washer to come in contact with the spring. The spacer tube has to fit inside the shim washer (Hence the need to open out the hole). I have also place a shim washer below the Type B bolt assembly just so you can see one. I DID NOT shim the Type B assembly.
I took out all the clutch plates for a visual examination. There were no bad marks and no significant glazing. The friction plates were serviceable. You should measure these with a micrometer, or possibly a decent Vernier, to check the thickness is over 2.35mm for all the plates except the inner most plate which should be over 3.15mm. There is not really much friction material on the plates and it is easy to miss-diagnose the serviceability of the friction plates. Mine had a noticeable ridge to the friction material, easily felt by running a thumb-nail over the ridge and were ‘in tolerance’. (A rough benchmark if you ain’t got a measuring device – there should be a detectable ridge to the friction material). The driven (steel) plates had a series of indentations stamped into them and there did not appear to be any significant wear on them. I do not possess a surface plate, so I could not check them for distortion. Here is a sample photo of the clutch plates (one resting on the clutch centre cover – viewed from ‘inside’ as it would be in the clutch basket assembly.



I then re-stacked the clutch plates in the basket and I used the red felt pen ‘match-marks’ to aid the correct replacement of the clutch centre cover. I then refitted the clutch springs, starting with the Type B springs first. These were progressively hand tightened using a diagonally opposite sequence as you would when fitting a wheel to a car. The orientation of the bots is relative to the long web cast on the clutch cover. From the starting point they go AB AB AB AB clockwise or anti clock-wise. So make sure you off start correctly & all will be well. WARNING ! – Only gently hand tighten the clutch bolts, then do the final tightening with a torque wrench. It is easy to over-tighten these bolts and strip the threads. It is advised that you stick to the lower end of the specified torque range. I use 8 lbs/ft for all the clutch bolts. Also remember the bolt lengths vary, with the shorter bolts being for the Type B assembly, which picks up into a steel spider on the torque back limiter assembly.
I then fitted and progressively hand tightened the Type A assemblies with the spacer shims. Care is needed here to ensure the shim is properly positioned and the spacer tube drops into the shim. You cannot see this, but if you carefully centre the shim the spacer will drop in place. Very much as ‘steady as you go’ operation. Bang it up tight to quickly and the shim might not sit right & it just acts as a thick washer to the original one, rather than a shim to pre-load the spring. Here is a photo of the reassembled clutch with the shimmed bolts highlighted with an orange circle.







You now need to readjust the clutch cable etc. BUT start with the screw & locknut adjuster inside the nearside (UK) transmission casing (Near the gear lever). Once that is set adjust the cable play at the handlebar adjuster. Do this before you refit the clutch casing as you can then do a visual check on the clutch action. With the shims in place the lever pressure had increased slightly, but is not ‘excessive’ and felt more positive. As mentioned earlier, the shim washer is only around 1.0mm thick. This visual check ensures that there is no coil binding of the shimmed springs. In this case all seemed fine, so I reinstated the clutch cover (Using the existing gasket which remained intact on disassembly) & torqued up the cover bolts. I refilled the engine with oil, ran it for a few minutes, then shut it down, let things settle, & topped up the oil. It does drop quite a bit if you have changed the filter.
The subsequent (approx. 40 miles) road test showed no signs of any clutch slip, and the drive out of corners seemed to be more positive with good tractive ‘bite’. The only downside, which is probably my failing, is that for about 35% of the pulling away from stationary I stalled the engine as the drive was being taken up. This was setting off on light throttle ant letting the last bit of the clutch out too quickly. This is just a difference in the biting point and the problem should go away as I get used to it and as everything ‘beds in’ again.
So there you have it …. You might be able to cure an ‘occasionally slipping’ clutch with just 4 washers and a bit of tinkering time. I would advise you, like I did, to have a clutch casing gasket ‘in-stock’ before you attempt this job – just in case it is needed. My original gasket does appear to have remained oil tight. If in doubt – change it as they only cost around £7 for a pattern part. (I re-used the original in case I had further tinkering to do – If I was going down the route of all new parts, then I would have fitted a new gasket at that point – this was an exercise to check out a ‘cheap fix’ that I’d read about elsewhere).
This ‘trick’ could be used on other bike clutches, but it might only be buying you a bit of time if the clutch is ‘on its way out’. The snag is you don’t really know what size to make the shims till you’ve got it in bits. I made two sets up to minimise messing once I’d got down to the job, but one of the sets would not physically fit the aperture in the clutch cover – so that was a pointless exercise.

  Yam

That is brilliant information Yam, thank you for that.   

Excellent Information and write up Yam  

Thanks Dave/Sim,
I see you've managed to 'restore' my text to a more readable format.   
I'm guessing I should 'paste' into the site using 'white' text.

Just thought this topic was worth researching a bit more ... & since joining the forum I had intended shiming the clutch ..... just waiting for the right time to do it.

Maybe one day I will get around to my K&N experiments for the standard airbox !
  Yam

Yes that's all I did, just changed the text to white.   
That will be great info for members to have plus the additional shiming your planning on doing.

Yam - that's a fantastic write-up - I'm bringing my bike up to your place !!  

Bizarrely, mine seems to be OK at the moment - maybe I've subconsciously adjusted my riding.  But if it starts doing it again, this is going to be the first thing I try - thanks again for a superb comprehensive write-up

Hello Yam,
A very good write up and Mod mate,, the VZ 800 is very well known for slipping clutch/week springs and I usually do this Mod rather than put uprated EBC springs in  ( which are easy to get in UK ), and if the VZ is tuned at all I do the washer Mod with new springs. I`m not aware of a problem with the clutch spring mounting bolts snapping on the VX as they have a habit of doing on the VZ,, I find it an oddity that the spring bolt torque on the VX is 9.5lb/ft but only 7lb/ft on the VZ and they have exactly the same clutch ( yep you can get a cable operated chain driven bike with back-torque limiter clutch) I`m always carful with tightening the bolts and am fortunate that I have a 1/4 inch drive in/lbs torque wrench ( 84in/lbs),,, I`m not aware of any problems VL owners have with clutch bolts. ,,, and a last point, I`ve mentioned to you that a friend has a Sachs 800 roadster that uses the engine from the VX 800, he has recently solved his clutch slipping by managing to use the cutch plates from, I believe, GSX 600 and he has managed to get an extra friction plate in,,, I need to talk to him more about that, it could be useful to other bikes.

Hi John,

Interesting to hear the chain drive VZ has a torque back limiter - it really is a 'forward thinking' feature for a bike from the early 90's.

The comment re bolt stripping etc. was passed on via the comments on the VX forum, I wanted to raise this as an issue because in effect they are only lightly tightened - and I too have the benefit of a light scale torque wrench (mine happens to be 3/8" drive). It is jobs like this where a torque wrench is (in my opinion) essential, and you have to trust when it 'clicks'  .... & NOT nip it a bit more for good luck !

It would be a bit hard to do this with ordinary hand tools, but if that was the case I'd say use a small 1/4" ratchet handle and nip it up till initial resistance from the solid feel of bottoming against the spacer tube is felt, then nip it about 1/2" more (Looking on the end of the ratchet handle).

But as said - this really is a job for a light scale torque wrench - and it would be best to borrow one if contemplating this job. (i.e. it is part of the 'preparation', before you start).

As you say it is an easy job to do.

I wondered John, when you do this mod, do you just shim/replace the 'Clutch - Type A' springs or do you do the back limiter springs as well ? ...... I only shimmed the  'Clutch - Type A' springs & the VX seems fine now.

There is the potential bonus that one set of springs can effectively do two bikes.  

I recall your previous comments re the Sachs 800 using GSX600 clutch plates .... & squeezing an extra one in ..... sounds like an interesting solution.

Cheers    Yam

Excellent write up Yam,very informative,and helpful.

Hello Yam,
I`m with you on this one mate, washers on the clutch side,,, but I use all the new springs supplied with the kit,, I`ve used EBC ,Vesrah, and Barnett,, I don't really have a preferred spring,  I think they are all much of a muchness in use.
I also have a in/lbs Torque screw driver, used to use it to torque the steering box worm drive pre-load on transit vans, it comes in handy now and again.
Again a good write up mate, so much so I`ve passed it on.

Cheers John,

...... & thanks for the support for the mod - It is always good when someone else can endorse a mod as being worthwhile.    I'm sure it will be of use to other forum members & their friends.

   Yam

So the LONG springs go into the Clutch Basket itself, SHORT springs go into the slipper clutch??  Im not positive but I think I reversed mine and it snapped the "Slipper" clutch cam.  In 3 places.

Also, when I put the new plates in, the pressure plate has a gap between the friction plates. about a 1/4" of play.  Is this normal can anyone confirm??

Hi DaNgEr,
The difference - length wise is actually in the bolts ..... whilst the springs are within 0.5mm of being the same length the back limiter springs are more open wound (Less turns).
From that I can only conclude that if you got the bolts in the wrong order it may have lead to some problems - but it is difficult to see how you managed to break anything in the back-limiter as the bolts should have 'bottomed out/gone tight before anything broke ..... also see my notes above about the relative low torque these bolts are tightened to ..... again if you were using a torque wrench you should not be in a position where something would break.

Anyway, that does not help your current plight .... The 1/4" of play does not sound right to me - & I would be suspicious that something has gone back in the wrong order - the first clutch plate in is different to the rest.
....... All I can practically suggest is that you strip the clutch down again and reassemble it carefully taking care to follow the workshop manual. I would slacken off your clutch cable & the 'inner adjuster' before re-assembling the clutch.

Hope that might help.  Yam

Ya I figured out what I did last night.
 
 The pressure plate was not in all the way. Not sure how it happened, but it did.

 It was short of being seated and when it was torqued, it must have been DOUBLE what I torqued it to, which in turn put extra tension on the back limter. I tried posting pics, it wont let me.


So anyways, Im glad in a sense that it happened, I have a better understanding of it now. Im not an idiot and Ive been working on cars and bikes since I was young.....Just not THIS particular model. Now I know

Hi DaNgEr,
I wasn't challenging you intelligence - I was merely offering a suggestion as to how to move forward from where you were. Sorry if you took it the wrong way.
The back-limiter clutch on the Suzuki 800s was quite an advanced step at the time it was first introduced ..... & I too had not come across this set-up until I got my VX.
Once you get your head around it (metaphorically) and set it up right (Stronger clutch springs - or shim the clutch springs - just the 4 doing the clutch function) then it works well.
Hope you soon get yours sorted .... sounds like you've sourced the parts you need - best of luck with the rest ... & you should soon be back on the road !
  Yam

NO MAN!!  Lol I didn't take it wrong at ALL!   I understand letters on a screen is difficult to decipher at times. Especially when you don't know a person yet.  I assure you I didn't take anything as a challenge nor the wrong way.  I can see how my rushed text looks like that. 

 Im not easily offended. (Thick skin here).  Thank you for offering your help and replies. I DO appreciate any help and responses I get.

 Its all good buddy :)

No worries buddy ... my aging skin is thicker than a Rhino's !
I just hoped I wasn't being a pompous  git (or coming across as one).
As mentioned ... I hope you are soon back on the road .... Cheers buddy Yam

Thank you sir. Me too! All I own is my bike.

 Actually I do have a question maybe you could help with.

 There is a tapered ring in between the friction/steel, (engine side)

 It came out of the stock set up. Do I need to put it back in the new clutch plates?  Ive never seen this.

Hi DaNgEr,

I think what you are referring to is known as the 'Wave' washer ..... & yes it needs to go in with the new plates etc.

If you can - try to access a Suzuki manual for the VZ ... it is shown on page '3.59 Engine' section, with a sketch to show the orientation of the taper. you should be able to access it from the forum site, but here is the page photographed from my copy.



The sketch is the second image down. If you copy the image onto you 'c' drive you should be able to enlarge it to read the detail.

Hope that helps you on your way !

  Yam

Yes that's it. Thank you for the reply AND the picture buddy.   I put everything back on in the same order, I just wasn't sure what it was or if it needed to go back on. 

 Thank you again!!

No problems .... happy to be able to help .... as one day I might need the help of others !

Hope you soon get back on the road !    Yam

You don't by chance remember the size of the nut holding the back limiter do you??

 Im at work and forgot to check it, a buddy is bringing me the socket I need, Thank you in advance!