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    Questions for Our Clutch Experts

    In searching the Technical Forum and "Old Q&A", I have noticed that there are questions and answers that deal with aspects of clutch work but not really a complete set of answers or descriptions of common clutch servicing tasks. Since my 1983 GS750ES now has the fairly common clutch rattle (at idle with clutch lever out, but not with lever pulled in, or at higher rpm's). I have developed a direct interest in the "clutch experience" of our members. Some of the previous answers leave unanswered some fairly basic questions about clutch servicing but even these simple aspects can be daunting to the "clutch newbie". Therefore, I have listed below a series of questions in an attempt to pull all or most of this information into a single thread. I think that it would be a great help to all of us GS owners if those of our members with clutch work experience would contribute their knowledge for the "clutch ignorant" (of whom I am a prominent example). Even if you only have experience or opinions on some of the questions, your selective answers would be of great benefit. So here are the questions (quite a number of them):

    1) Do our clutch experts think that the common clutch rattle (described above) is caused by worn/broken rivets and/or damper springs in the clutch basket? Could a worn thrust washer also be to blame?
    2) Can clutch work be performed by an owner with average mechanical skills and commonly-available tools?
    3) Can the work be performed with the bike on the sidestand without first draining the engine oil? Would you just lose about a quart of oil this way when removing the clutch cover?
    4) My service manual mentions using a "special tool" (a "conrod holder", which assumes the top end of the engine is disassembled?) when removing the 4 clutch spring mounting bolts. Is this to stop the clutch assembly rotating? How does one do this without the use of a special tool? What common tool can one use?
    5) After removing "the spring, pressure plate, push piece, thrust bearing, drive plate and driven plate", then the "clutch sleeve hub nut and lock washer", my service manual then instructs to remove the "clutch sleeve hub" using another special tool ("clutch sleeve hub holder"). Again, can the clutch sleeve hub be removed without a special tool? Can you just put the bike in gear and have someone stand on the rear brake? Is there a better way?
    6) After removing the clutch sleeve hub, and pushing the spacer and bearing backwards, my service manual says the "clutch housing with oil pump drive gear" can be removed. Is this "clutch housing" the "primary driven gear" referred to in many parts diagrams/fiche? Is it also what is commonly called the "clutch basket"?
    7) I cannot find a separate part number for the "damper springs" in the clutch basket on BikeBandit.com. Can one just buy the springs, rather than the whole basket?
    8 ) Are the springs easy to remove and replace? Is there a special technique or use of a common tool to do this?
    9) If the rivets are worn, can they usually be drilled out and replaced? What sort of place can usually do this locally, without having the delay of sending the basket off somewhere to get this done?
    10) Is just buying a new basket ($153 from Ron Ayers for my 1983 GS750ES) a reasonable alternative in terms of cost? Would a new basket usually include the damper springs, or are these a separate item normally?
    11) While the clutch is apart, would you recommend replacing the metal and friction discs/plates and clutch springs as a routine procedure if the clutch has had over 30,000 miles of use? Any preference for OE Suzuki plates and springs vs. Barnett vs. Vesrah vs. EBC equivalents?
    12) Would you also replace the thrust washer as standard routine procedure?
    13) When reinstalling the clutch hub, the service manual notes to "check that the rubber damper plug is in position behind the clutch hub". What is this "rubber damper plug"? Does it get worn by use and should it be replaced as standard procedure? I can find no picture showing this part in the manual or on the parts diagrams.
    14) Should one use a new tongued/tabbed lock washer when reinstalling the clutch hub and nut?
    15) I understand that new friction plates should be left to soak in clean engine oil for a period of time before installing. For what period of time should this be done?
    16) I know that the metal and friction plates have to reinstalled in a particular order. Is there any orientation of the individual plates that should be used? I assume that it is a good idea to keep the original "pack" of plates together as a "go by".
    17) I note that the clutch spring bolts should be tightened diagonally, and by degrees, to a fairly low torque level (8.0 ? 9.5 lb-ft for my bike). I assume a standard, large torque wrench (17" length. 150lb-ft limit) is too big/inaccurate for this task. Would you recommend getting a smaller torque wrench for this task? Where is a good place to get one and what do they typically cost? I am concerned about this because I assume that even torque on all 4 bolts is important and I am also aware that some members have stripped these bolts or the plate (no names!).
    18 ) I assume that a new gasket is usually necessary when replacing the clutch cover. I can't find a part number for this gasket on BikeBandit. Would BikeBandit or Ron Ayers normally carry them, or is this a "dealer only" item?
    19) My manual also specifies using "Suzuki Bond No. 1207B" on part of the cover mating surface. I assume this is a gasket cement/compound. Does anyone have a brand of compound they prefer, and where can you usually buy it.
    20) Are there any items or "gotcha's" that I have missed, and need a warning here?
    21) Finally, how long might the whole clutch servicing job take? Given my painstaking methods, I shall probably multiply any answer by at least 2 or 3!

    I know that this is a long list of questions but I think it would be good for our members to have all this information on a single thread. My thanks in advance to our clutch experts who take the time to provide these much needed answers.

    Simon Waters

    #2
    2) Can clutch work be performed by an owner with average mechanical skills and commonly-available tools?
    3) Can the work be performed with the bike on the sidestand without first draining the engine oil? Would you just lose about a quart of oil this way when removing the clutch cover?
    21) Finally, how long might the whole clutch servicing job take? Given my painstaking methods, I shall probably multiply any answer by at least 2 or 3!

    2)Yes All that is needed is a few common hand tools that can be obtained from any parts/hardware store.
    3) No You will lose a lot of oil.An easier way is to lay the bike over on the side on an old tire etc. so you don't scratch it.
    21)The first time I changed my clutch springs and checked the plates it only took 1/2 an hour including all measure-ments.Springs were the reason for clutch slipping at high load WOT.Bike has 33K miles now and the clutch plates still have a LOT of hard miles left in them.

    Comment


      #3
      I am by no means a clutch "expert". However, the following is based on my (fairly limited) experience with clutches:

      1. I don't think this is a damper spring problem, since it goes away when you pull the clutch lever (the damper springs should move the same whether or not you have the lever pulled in).

      2. Yes.

      4. and 5. As far as I know, you don't need the special tools. I've always accomplished the same thing just by putting the bike in gear and holding the rear wheel in place with a 2x4.

      6. Sounds like the "clutch housing" and "clutch basket" are one and the same. This is also called the "primary driven gear assembly", I believe.

      7. and 8. Damper springs are an integral part of the clutch basket. You may be able to find a shop that will take the thing apart and replace the springs, but I couldn't. The damper springs should be fairly snug in their recesses. If they rattle around when you shake the clutch basket, you may need to replace it.

      10. The new clutch basket includes dampers springs.

      11. It's definitely worth measuring the plates while they're out, to see if they're still in spec.

      17. I shelled out for a micro-adjustable torque wrench a couple years back, and have never regretted it. Speaking from experience, it's possible to twist off a clutch spring bolt without even coming close to the 8.0 ft-lb minimum. In hindsight, other worn clutch components (e.g. damper springs) may indicate rough use of the clutch by previous owners, and it sounds like the clutch spring bolts are one of the first things to go -- you may want to replace these if other clutch components are worn.

      21. If you have all the parts you need, you can easily disassemble, inspect, and reassemble the clutch in a couple of hours. The trouble for me has always been, if I don't know exactly what the problem is beforehand (which is generally the case), then it's hard to know what parts I might need.

      Michael

      Comment


        #4
        14) Something that wasn't discussed is the availability of an APE clutch hub nut. They say that the centre nut can come loose and make the hub wobble.

        Another thing, my manual says to replace some sort of piano wire contraption every time the clutch is pulled apart.

        3) You will lose oil, there is a racing clutch cover available to prevent this but it is pricey.

        4) It is possible to fabricate a large oil filter wrench to hold the clutch in place. I had one for my snowmachine and it worked very well. On bikes you can use the brakes.

        9) APE and Star racing sell the rivets and all parts necessary to have a local shop repair the basket for you. It's about 100$US for everything but you retain the gear and basket. I think the rivets themselves go for 10$US

        18) Star sells a bottom end gasket kit including the clutch cover for 20$US

        Steve

        Comment


          #5
          I don't know if I am an expert, but I have replaced clutch plates and put in new clutch springs a number of times.

          1. First of all you ask whether you need special tools or not:
          No, I just used common everyday tools.

          2. You ask if you need to drain the oil.
          Actually, I replaced clutch springs without draining the oil.
          I placed the bike on the side stand, and I did not loose a drop. I even reused the gasket (I had given it a new gasket a couple of weeks prior to the operation though).

          By the way, the bike is a 77' GS750.

          Comment


            #6
            I drag raced for 15-20 years....so I have met Mr. Clutch a few times. I always drain the oil...put it on a stand or center stand...thats my preference. The rattle is the clutch hub backing plate springs...trust me. Send your hub to falicon and have it rebuilt...it will be better than a new one. To do things right you might want to have a air wrench handy...you have to know how much to torque with one of those...APE nut is good investment. Take the nut off before you unload the clutch. Check the inner hub well for grooves cut by the plates. Use OEM parts...again trust me. You can easily shim your clutch springs if you do not want to invest in new ones...watch for coil bind. Make sure the metal plates are flat...bead blast them before reinstallation...check the wear on your fibers...abuse has more to do with plates than miles. You asked so many questions I can`t remember them all...make sure you get your oil pump back in time and correctly engaged. If you think your clutch rattles you should hear a 79 cbx...most like me has retofitted a 81/82 clutch to eliminate the problem. Good luck!

            Comment


              #7
              Forgot to tell the reason for sending it to falicon...they rebalance thier hubs...something that needs to be done.

              Comment


                #8
                are the clutch outer hubs in a 750e the same as in an 1100e or an 1100g???

                Comment


                  #9
                  I think there is a different ratio used...not certain.

                  Comment


                    #10
                    Originally posted by cbxchris
                    I think there is a different ratio used...not certain.
                    ok i think i remember--and straight cut gears on the 750 also--I was just thinking of the basket size itself.

                    Comment


                      #11
                      slightly off the beaten path, but does anyone have any ideas as to what would be going on if I can hear a rattle at idle whether the clutch lever is in or out???

                      Comment


                        #12
                        Originally posted by Browndog
                        slightly off the beaten path, but does anyone have any ideas as to what would be going on if I can hear a rattle at idle whether the clutch lever is in or out???
                        Could be worn damper springs, I think. What happens when you give it a bit of gas at idle?

                        Michael

                        Comment


                          #13
                          its the backing plate springs...there are two sets in there. if its bad enough you need to either replace the hub or send it to falicon.

                          Comment


                            #14
                            My thanks to all who have replied and contributed their knowledge.

                            I suspect that the clutch basket rivets and/or damping springs may be the cause of the rattle but I guess I will have to do a preliminary inspection to see what parts need to be replaced. Interestingly, I had no clutch noise at all until I took my bike into the dealer for a new drive sprocket and chain 2 years ago. When I picked up the bike, the rattle was immediately evident, so I returned it to the dealer for them to investigate. They proclaimed ignorance as to the cause and tried (and charged me for) a carb balance to smooth the idle. No improvement in the noise as the carbs were pretty well balanced already. They also masked the problem somewhat by raising idle speed to 1600 rpms. At that time, I had not had the benefit of the education available on this site. I now wonder if the mechanic who installed the drive sprocket could somehow have damaged the clutch by wrenching on the sprocket bolt too hard while the bike was in gear. Any thoughts on that? I did resolve never to use the service department of my local Suzuki dealership again for that and other reasons.

                            I will look for a micro-adjustable torque wrench (thanks, Michael) for tightening the clutch spring bolts (carefully!). What do most people use for measuring clutch plate thickness and free spring length?..a micrometer or caliper? Any recommendations for brands or sources of these 2 items (e.g. Sears, Checker Auto, etc.)?

                            One last question: I know I have to apply a small amount of gasket cement (in addition to the gasket) to the mating surfaces where the 2 crankcase halves join. What brands of gasket cement do you think works best and where do you buy it?

                            Comment


                              #15
                              the rattle goes away with a bit of throttle, but not till almost 2500 revs.

                              Comment

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