gsx1100g clutch gone

[gandy666]

hi, so the hydraulic clutch on my GSX1100g has gone altogether.

there a few kits around on the net. anyone who's done a clutch rebuild before, do I just need the friction plates, or do I need the full kit with separator plates and springs? bike has only done 18000 miles amd i haven't thrashed it.

bike was laid up for a while so assuption is the friction plates dried out and with me using the bike pretty regularly now, the friction plates have disintegrated. cltuch was absolutely fine til last week, then the pressure went in the lever, assuming cos the friction on the plates went. i bled them through, now the engine spins when I change gear.

also. do I need to change the oil when I change the plates?

How easy a job is a hydrulic clutch rebuild ? anyone got some instructions?

[Chrissb6]

Here's the place for the bits

hhttp://www.wemoto.com/bikes/Suzuki/GSX ... -96/#CLUTC

I would suggest fresh oil, and make sure you a re useing the correct oil, the wrong oil can trash a wet clutch.

[Tango]

On a lot of bikes the clutch plates can be replaced without draining the oil....but you have to keep the bike on the sidestand. Unless the plain plates are warped you shouldn't need to replace them....but maybe clean them up when you have the clutch apart. Personally I'd replace the springs while the clutch is apart....not generally too expensive and worthwhile to eliminate them from any further trouble.....

Haynes manual is your friend.....good investment if you don't already have one....

Remember to soak the new friction plates in clean engine oil for several hours (or overnight) before fitting them......also check the clutch basket for notching while you have it apart...

Also remove the slave cylinder when it's all apart and check that the push rod moves freely without any binding etc.

Relatively easy job that doesn't normally require any special tools.....

[gandy666]

thanks for the replies guys.

done a bit of research and I may have overfilled the reservoir when I changed the fluid and bled the system on Sunday.

makes sense - brake fluid expands as the cable goes over the engine, thus engaging the clutch, thus the problem only occurs when the bike has fully warmed up. didn't happen until 38 miles into a 40 mile journey. same last night. certainly was not a problem before I lost clutch pressure on Friday.

sounds feasible and I can do it by the roadside afore I drive tonight - just have get a straw and sook some fluid out.

will let you know how I get on.

[gandy666]

no haynes manual for this bike.

have an online PDF which is not particularly comprehensive and is quite a faint copy.

read elsewhere I need a 50ml socket to get the the clutch basket off.

hopefully a sook with a straw will sort out the level of the reservoir

[uk190]

i am a tad confused as to what is actually wrong with the clutch. can i get you clarify a few things?

1. when cold, does the clutch slip or does it fail to disengage the drive (so you cant change gear)

2. does it slip when hot?

3. do you lose lever pressure after a few pulls of the lever?

4. what engine oil is in it?

5.what does "engine spins when i change gear" mean?

6. when you bled it through, did you just top up the old fluid with fresh or drain all the old fluid out first?

[Tango]

i am a tad confused as to what is actually wrong with the clutch. can i get you clarify a few things?

1. when cold, does the clutch slip or does it fail to disengage the drive (so you cant change gear)

2. does it slip when hot?

3. do you lose lever pressure after a few pulls of the lever?

4. what engine oil is in it?

5.what does "engine spins when i change gear" mean?

6. when you bled it through, did you just top up the old fluid with fresh or drain all the old fluid out first?

Martin...this is kinda a continuation from another thread. Basically the master and slave cylinders have been stripped and cleaned, new fluid and bled.....I'm guessing that the motor spinning when changing gear is the clutch slipping when shifting up through the box. Seems it slips more when hot....but as the OP has said he thinks he may have overfilled the system so when the fluid expands when hot it's got nowhere to go except possibly disengaging the clutch slightly....

[eastanglianbiker]

you cant over fill the system with fluid as the master cylinder will only hold a certain amount of fluid and if you have put to much in then it will overflow as you put the rubber seal on before the lid

[uk190]

bob. the thread wasnt clear on what exactly was wrong. slipping or sticking. he also mentioned losing lever pressure.

clutches are a simple concept made slighlty complex by the amount of components.

if it slips... worn clutch or friction plates. worn pressure springs. wrong oil (anti friction additives).

if it sticks... contaminated fluid. failure of master or slave cylinders. knackered hoses. sticking plates (especially if it has been stored and not ridden). damaged plate fingers. damaged basket. bent plates.

am not convinced about the fluid heating and expanding. it would need to get very hot to expand fresh fluid enough to overcome the spring pressure. as the clutch lever is not being pulled and the piston in the master cyl moved then the fluid in resevior and hose are "connected" so it would more likely leak out through the filler cap seal.

its the same fluid used in brakes remember and calipers get hot hot hot. if that were the case then brakes would be self operating when they get hot. they dont, they fade because the fluid boils and becomes compressable. hence the spongy feeling.

i asked for clarification as the phrase "so the hydraulic clutch on my GSX1100g has gone altogether." is a bit vague.

[eastanglianbiker]

the choices are rebuild master and slave cylinders ,replace hose from master cylinder to slave cylinder,drain oil replace clutch plates and rebuild with fresh oil so no clutch plate contamination is present.so as martin says is it working to put bike into gear then slipping as you try to pull away or under load or is it not even allowing you to put it into gear?

[gandy666]

hi guys

thanks for the replies

clarification:

1. when cold, does the clutch slip or does it fail to disengage the drive (so you cant change gear)

when cold, clutch is absolutely fine - behaves as expected. I can change gear, I can drive off, there is no slippage.

2. does it slip when hot?

yes, after about an hour or so of driving.

3. do you lose lever pressure after a few pulls of the lever?

no the pressure remains constant - the lever feels more 'springy' after about an hour which makes me think the pressure is building up, the expanded oil has nowhere to go, so it starts to push out the clutch piston which pushes the clutch rod in. there is no leakage of clutch fluid anywhere and there is no indication of the level in the reservoir, probably because the level does not come down to the observation window.

4. what engine oil is in it?

Its new Motul 5100 10w40. I also fitted a new oil filter and I checked its at the correct level on Monday.

5.what does "engine spins when i change gear" mean?

sorry this isn't clear - after about an hours driving i change gear, it goes into gear, give it some revs and the clutch slips and there is minimal power getting to the rear wheel. I can actually put it in gear, let out the clutch and the engine does not stall.

6. when you bled it through, did you just top up the old fluid with fresh or drain all the old fluid out first?

i drained all the old fluid out first, blew it through, took the slave cyclinder apart, cleaned it out, then bled through with fresh fluid. Judging by the pressure at the lever, there is no air in line or in the slave.

the clutch is not sticking - it begins to slip after about an hour of driving.

when I filled the reservoir, apparently there is a fill level line, which I did not notice. it was right to the top, I put the seal on, and a little flowed out which I mopped out. Its filled right up so i would expect that even a slight expansion will have an affect.

[Tango]

am not convinced about the fluid heating and expanding. it would need to get very hot to expand fresh fluid enough to overcome the spring pressure. as the clutch lever is not being pulled and the piston in the master cyl moved then the fluid in resevior and hose are "connected" so it would more likely leak out through the filler cap seal.

its the same fluid used in brakes remember and calipers get hot hot hot. if that were the case then brakes would be self operating when they get hot. they dont, they fade because the fluid boils and becomes compressable. hence the spongy feeling.

i asked for clarification as the phrase "so the hydraulic clutch on my GSX1100g has gone altogether." is a bit vague.

I was just trying to point out that there is another thread with the beginning of this story...so to speak.....

Yeah...I agree Martin and EAB......the clutch fluid would get nowhere near as hot as brake fluid could. My money is going to be on worn friction plates or springs....especially as the bike was laid up for a time....so the friction plates could have dried out and now have glazed.... However, there is also the possibility that the clutch actuating rod may be sticking and not releasing correctly....or as you pointed out the clutch basket could be notched.

As you say Martin, the clutch is a relatively simple device but contains a lot of parts....and especially when it has a hydraulic clutch operating mechanism rather than a simple cable....

[gandy666]

actually the oil is 10w40 Motul 5000.

The clutch fluid is getting pretty hot as the cable goes under the tank, over the head, the length of the engine.

before I bled it, the oil had pretty much turned to a petroluem jelly consistency in the reservoir, tho maybe it was because it was old.

all the old stuff was blown out so confident its cleared

[Tango]

Well I guess the acid test will be to remove some fluid and try it out......start with the simple stuff.....

[megawatt]

I wonder if you have used two different types of clutch fluid that have reacted with each other?

When the clutch slips is there free play at the lever. If there is, the problem is within the clutch itself, either wrong engine oil or plates warped/worn. If there is no free play, the clutch actuator rod could be sticking in the engine casing. I had this with my Bandit12. stripped and cleaned everything, new seal and all was good !

[gandy666]

dunno what was in, but I blew it all out anyway and used dot 4 from one cannister.

have my straw at ready to remove a half cm or so

[megawatt]

What about the second question? Free play at lever?

[uk190]

Sweepstake time... place your bets.

I'll bet my 50p on it having worn friction plates. As the engine warms up the oil viscosity changes making more slippery this reduces its drag effect between the plates leaving only the friction surface to grip the clutch plates. Which fails because they're worn. Causing the clutch to slip when the engines hot.

I can't see bent rods or plates or damaged baskets getting worse with a warm engine.

[megawatt]

I reckon worn friction and blue steels brought on by wrong oil?

[gandy666]

no play at the lever.

I'll bet too much fluid in the reservoir.

hope its this cos the others will cost a few bob

[eastanglianbiker]

i going with friction plates as well

[Tango]

Sticking actuation rod.....(favourite was friction plates but that's already gone....).....

[gandy666]

so, draining some brake fluid out of the reservoir had no effect. still started to slip about 40 miles into my journey.

next cheapest thing for me to try to change the oil. I have semi synthetic 10W40 in it. Manual says 'use SAE10w40' but does not specify whether it should be synthetic, semi or summat else.

anyone aware why there would be a problem using this oil in my 20 year old bike? could it be getting too thin when it heats up and this causing the slip?

what type of oil should I be using if semi synth in not appropriate?

By the way, this is a shaft drive - there is the hydraulic clutch in there, but is there something else clutch like at the shaft that could slipping?

[megawatt]

Some old Suzukis didn't like fully synthetic oil. If yours doesn't, you would need to soak the friction plates in degreaser or probably replace them for uncontaminated ones. Have a look at the steels. If it is slipping they should be blue and dished.

[gandy666]

has semi synthetic in at the mo.

have heard that fully synth is for more modern bike.

if synth is 'the best' and semi is the next best, whats after that? maybe thats what i need