Grabby Clutch when Cold - Solved! - Secrets Revealed . . .

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by MotoTex, Jul 30, 2012.

  1. MotoTex

    MotoTex Miles of Smiles

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    2,020
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    After experiencing a particularly annoying issue where the clutch would engage suddenly, instead of smoothly, especially when the motor had not warmed up. I'd describe it as "grabby" or "snatchy." Let out the clutch to the engagement point and then it would suddenly become fully engaged.

    This resulted in many, many instances of a stalled engine, and one tip-over, as I began a right turn while pulling away from an intersection (with a cop at the intersecting stop sign, how embarrassing).

    I had been hating going for a ride because of this. Stalling like a newb all the time. In front of friends, co-workers, strangers, the self-imposed trauma was debilitating to my desire to take the beast for a ride. (not to mention the successive blows to my inflated ego! :lol3)

    Once it had warmed up, or, after some unknown period of riding, the problem would disappear and everything would return to normalcy.

    As I had an oil change due it seemed appropriate to take advantage of this special moment to dig a little deeper into this ever-more-maddening clutch. The problem had been infuriatingly intermittent, and seemed to be getting worse toward the end of life for the oil.

    There had been an attempt to address this once before. A few months ago I had placed the bike in left-side nap mode, taken the clutch apart, and had verified that #12 thrust washer next to the Bellville Spring had been removed, and I cleaned the oil jet with a High E guitar string. Both, after reading about these possible fixes in the HOW and various threads in the OC.

    This time I read every clutch thread I could find and made notes of the things folks mentioned that I felt might have an effect, or be worthy of inspection.

    All my steels measured 2.0 mm. Midrange on the wear spec. The friction plates ranged from 2.63 to 2.68, a little worn from the 2.8 mm spec. These are at replacement stage, but I'll try to get a little more life out of them. They are likely stock, and this bike has a little over 40K miles on it.

    One thing I found in the HOW was a reference someone posted about the service manual indicating that during clutch assembly the steels all need to be oriented with the "rounded" edge on the same side. The OEM steels are stamped, and one side is a sharp edge and one side is rounded from this process. One poster indicated that they always put their rounded side "OUT" towards the pressure plate. The manual wasn't specific about IN or OUT being preferable, other than that they all needed to be installed the same.

    I chose to put the rounded side facing "IN," as that is the direction of engagement and I wanted the least possibility of it hanging when they are sliding that way along the basket guides.

    BTW, during disassembly I had indeed found that three of the steels were reversed from the rest. Also, I had found the outside friction plate had been installed in the rest of the pack and a standard steel/steel friction plate had been running duty in the special steel/aluminum friction plate spot next to the pressure plate.

    An important part was learning the way to identify the "special" outer friction plate is not by any number stamped on it, but, by looking at the friction material shape. The blocks of friction material are wider on the special one. All of the friction plates may have A11 or A12 or some such nonsense stamped on them. This number has no relationship to the friction material on that plate.

    This thread was very helpful in making this clear and helping positively identify the correct plates.

    I put it all back together, Bellville Spring with the ID pointed OUT (which I've since noticed in a photo from the above linked thread is backwards to how I should have installed it), special inner steel/aluminum interface plates with the larger ID to accommodate the Bellville Spring, then alternating steels and frictions with the rounded side of each steel facing IN, and lastly the "special" friction plate on the outside and offset from the rest of the stack.


    The clutch now works like it should!!! :clap :freaky

    I believe that it was most likely the three reversed steels that were getting into a bind with adjacent steels, until things warmed up, expanded, got lubed or whatever.

    I hope this helps someone else get this solved without having to spend hours gleaning info from the OC and the HOW, taking copious notes, and R&R'ing their clutch multiple times.



    On only a marginally related note, I replaced the drained Rotella T6 with Amsoil MC oil.

    I think that Rotella T6 is only okay for our beasts. It is lacking many of the necessary additives that true motorcycle oils have for lengthening their lifespan while performing multiple duties lubing engine, clutch and gearbox. This is essentially a combination that is like a Quisenart for motor oil. If you can't find anything else, you can use Rotella and change it often. Otherwise use a four stroke specific motorcycle synthetic oil for best overall performance and longevity in this harsh operating environment.

    After reading a lab-tested comparison on most currently available oils for motorcycle application I found that Mobil 1 and Amsoil Motorcycle-specific oils performed the better in comprehensive testing and kept their qualities the longest.

    Amsoil was the overall winner in the categories I felt were more important to me. My local auto parts store carries it. At about $12 a quart it is a buck more than the Mobile 1 MC oil. I'll be using this in all the bikes now. Still less than Motorex, and likely a better oil for the job.

    Via con dios!
    #1
  2. avocadofarmer

    avocadofarmer Fruit Coot

    Joined:
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    I've got 6k miles on mine running Rotella T6 and nary an issue with clutch slip or grab...

    To each is own!
    #2
  3. MotoTex

    MotoTex Miles of Smiles

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    I appreciate your sharing this, but let me be clear. The oil was NOT being cited as a contributor to the clutch issue. Hence, the "on only a marginally related note" comment prefacing the bit about the oil. A disclaimer of sorts. I've edited the original post to avoid creating any confusion about this.

    Probably should have avoided making any comment about anything as religiously debated as oil at all. :huh

    If you haven't noticed any degradation in shifting over time using ANY oil in an LC8, you probably won't notice what I am talking about with Rotella T6. It just happens quicker (for me) with Rotella than it did with other motorcycle-specific oils I've used while putting 25K miles on my Adventure over the past year.

    This shifting symptom is a fairly well known indicator on an LC8 that it is time for new oil. (nothing about clutches slipping or grabbing being mentioned here, just a little clunkier shifting)

    This symptom is due to the shearing of oil in the transmission, braking down the additives.

    Rotella is designed for use in diesel engines. It was not designed for use in transmissions. Rotella does not contain sufficient amounts of the specific additives necessary to provide longer service life in an environment where an oil that was built to have more of these slippery bits will. All "motorcycle" oils are (allegedly) designed for this unique environment where engine, clutch and transmission share the same lubricant. Some are better than others at this task.

    For me, this means replacing Rotella at least twice compared to using a motorcycle-specific synthetic. Based entirely on shifting performance that I can feel. Cost savings is then just about nil over time.

    YMMV, or, "to each his own"

    Thanks for growing the avocados. :clap I had some on a couple of tacos for lunch!
    #3
  4. Off Road Ryder

    Off Road Ryder Long timer

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    Thanks Mototex.. I also have the sometimes embarrassing grabby clutch when cold. I noticed after cleaning the oil jet it got better, but never would go away.I have also had everything apart looking for any issue twice.:huh
    I will pull my basket apart and check out the plates, I know I did not pay any attention to what side is what when removing my Reckluse.
    What a great site this is.
    #4
  5. alkiviadis

    alkiviadis Adventurer

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    Greece N' around.....
    Thank you for sharing!:thumbup:thumbup
    #5
  6. HellsAlien

    HellsAlien a has-been that never-was

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    MotoT,

    Thanks for contributing to the collective. I find the rounded edge of the steel plates idea interesting and will check my plate stack for that. I'm not sure which camp to be in on that, round edge out or in; might try both. I bet that when I get in there I will find wear on my 56000 mile clutch basket though, so my wallet is in no hurry to find out!

    I removed the belville spring from my clutch stack a few years ago. That helped me reduce clutch drag significantly when hot, but allows mucho chatter when cold, for me an acceptable compromise. I did similar on my Triumph with good results too.

    I use similar oil for same reasons as you, though I feel the quality & weight of the base stock is more important than the additive package. In my experience, Mobil 1 bike or car oil ranks at or near the top of my "engine happy" scale.

    Happy trails...
    #6
  7. walstibsf

    walstibsf ADVENTURE-HOLIC

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    M-TEX: great write-up! Lots of useful detail. THANKS!

    As for running automotive and diesel oils: these have friction modifiers which may not be the best for a wet clutch. So....I wonder.....

    Also, motorcycle specific oils(i.e. mobile 1) have ZDPT(zinc), phosphorus and other anti-wear/anti corrosion additives more specific for our cylinder bores and high revs. just for thought.......
    #7
  8. dogsslober

    dogsslober No neck tie, Ti neck

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    I've been having the same grabby clutch and thought it was just the nature of the beast. As soon as iI get a chance I'll look at my plate's. Thanks Moto Tex:clap
    #8
  9. Nailhead

    Nailhead Free at last!

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    Longmont, CO
    Precisely my experience.
    #9