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Thread: No adjustment left in Clutch rod?

  1. #1
    Registered User gertiektn's Avatar
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    No adjustment left in Clutch rod?

    I just was getting used to my latest purchase a 75/7. On first ride I noticed the clutch was graby. I noticed that as you let out the clutch there was not much slip room. The clutch is good and engaged solidly. I rode the machine in traffic and as it got hotter and on the way home from 20 miles out, it gradually was dragging more and more then it finally would not dis-engage..

    Lucky the I was able to pull of and get to a lot and pull out the tool kit. At first I was suspect of the cable pulling apart as the lever gap open up so the the cable was not fully disengaging the clutch. My adjustment at the bars was out to the max. I next checked the clutch pin adjustment. There was about 1/16" adjustment between the 10 mm and the 13mm lock nut.
    I was able to take up the adjustment as the 10mm does not take much to bring in back to adjustment. I screwed in the handle bar adjustment and set the rod, watched the action and the 90 degree angle. I set it and the lock nut , then did the final adjustment at the handle bar..
    I was able to continue on and all seemed normal.

    I purchased a new cable and installed it today. Question, all works as normal except that all the rod adjustment all used up, is this ok? Can I get I a longer 10mm bolt?
    Any ideas on what is going on here?
    I plan to ride this bike from Denver to Seattle next week.
    Thanks for any input.

  2. #2
    Registered User skiteach's Avatar
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    Did you screw the handle bar adj in as much as possible? (sounds like you did). Longer bolt could be substituted, should not be necessary. Might be worn disk. The only way I would use a longer bolt would be temporary.
    '73 R75/5
    Never had a bad day skiing!

  3. #3
    Administrator 20774's Avatar
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    Here's the procedure for clutch cable adjustment provided by Tom Cutter on the Airheads list. I had never used this before, but after replacing the cable and using this procedure, the clutch seems brand new...it's like I have more power in the engine. Worked for me... The key thing to realize... the hand lever adjustment adjusts the freeplay at the back of the tranny; the 10/13mm adjuster nut/bolt at the back of the tranny adjusts the hand lever freeplay. Weird, huh!

    ------------------------
    Do a complete, "from scratch" cable adjustment after replacement. To do this:

    1) Replace cable, both ends now disconnected.

    2) Loosen locknut at transmission lever, slacken adjuster screw several
    turns out.

    3) Insert top end of cable through adjuster, into the lever slot, pushing it
    WAY in to the lever. Slip the greased barrel up onto the cable, and pull the
    cable back to engage the barrel on the cable. Clean and examine all parts to
    see that the barrel only goes in one way.

    4) If the cable is routed properly, and the top barrel seated correctly, you
    should be able to hook the barrel on the lower end into the forked clutch
    arm at the transmission.

    5) The first adjustment is made with the large threaded adjuster at the top,
    lever end of the cable. You need to measure the cable dimension at the LOWER
    end, and make the adjustment at the TOP end. The dimension should be EXACTLY 201 mm from the rear face of the transmission where the cable comes through, to the near edge of the cable barrel. You may need to turn the top adjuster out quite a ways to obtain that dimension. Squeeze the clutch lever and
    remeasure, as that will seat everything. The easy way to measure the 201 mm is to cut a piece of coathanger to the exact length and use it as a guage. Put a piece of duct tape on the middle like a flag, write "BMW Clutch Adjustment 201mm" and you got a free BMW Special Tool.

    6) The second adjustment is made at the rear of the transmission, using the
    adjuster screw and locknut on the clutch arm. Turn the adjuster bolt in until
    there is NO free play on the cable, determined by lightly pulling the lever
    with one finger and looking at the gap at the hand lever where the cable
    passes through. Once you have removed all free play, back out the adjuster
    just enough to give 2-4 mm freeplay at the hand lever. To hold the adjustment
    while securing the locknut, just pull and hold the clutch in with your left hand
    while snugging the locknut with your right hand.

    ---------------------------------------
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  4. #4
    Registered User skiteach's Avatar
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    RM needs to try this adjustment procedure.
    '73 R75/5
    Never had a bad day skiing!

  5. #5
    Registered User gertiektn's Avatar
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    Thanks guys, I will make the tool measure and see if it has any affect on the rod adjuster. Will report back.

    I have come to the notion that the clutch was not adjusted correctly in the first place and when the machine heated up completely the friction from the plates it all caught up to its self, it was gradual over a short period but I was definately happy to have my tool kit up to speed.

  6. #6
    Registered User gertiektn's Avatar
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    Ok, I have the exact 201mm from casing flange to edge of lever barrel. The handle bar adjuster has about 10 threads in the upper lever bracket, then the lock barrel. The adjuster at the bars have 15mm of thread exposed out side of the lock unit.

    The 10mm cap screw at of the trans has maybe one turn left in it. All seems to be working well. There is 2 to 4mm of free plan on the lower lever. That translates into about 3/4" free play at the outer end of the clutch handle bar lever.

    Maybe I am worrying about nothing. I need to drive it 1500 miles, then plan a major strip down and will most likely will pull the transmission out for a full inspection and fix as necessary..

    Comment are appreciated.

  7. #7
    Administrator 20774's Avatar
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    Quote Originally Posted by gertiektn View Post
    The 10mm cap screw at of the trans has maybe one turn left in it. All seems to be working well. There is 2 to 4mm of free plan on the lower lever. That translates into about 3/4" free play at the outer end of the clutch handle bar lever.
    The free play at the lower lever sounds about right. The arm at the back of the tranny should be near parallel with the back of the tranny case. There's no free play spec given but as long as you've measured the 201mm correctly and there is some but not much free play you should be OK.

    I'm not sure I'm understanding the 3/4" free play at the outer end of the hand lever. The measurement I would want to hear about is the amount of gap opened up between the movable hand lever and the fixed perch. There should be a 2-4mm of gap opened up according to what Tom Cutter posted. Again, you want a little bit of free play at the hand lever...this is mostly a "comfortable" adjustment. But the 3/4" at the outer part of the hand lever...I don't know what that is...sounds like a lot.

    Another source of slop you might have could be the nylon bushing that the hand lever pivots on. If you move the hand lever vertically, the ball end of the lever should move no more than say about 0.125" or so. If it moves more than that, the bushing could be wallowed out giving you uncertainty in the clutch lever. It's not critical to replace this immediately, but when I replaced mine, it made the using the hand lever a lot more solid...just felt a ton better.
    Kurt -- Forum Administrator ---> Resources and Links Thread <---
    '78 R100/7 & '69 R69S & '52 R25/2
    mine-ineye-deatheah-pielayah-jooa-kalayus. oolah-minane-hay-meeriah-kal-oyus-algay-a-thaykin', buddy!

  8. #8
    Registered User gertiektn's Avatar
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    Good info, I agree the perch lever bushing is most likely worn, there is a lot of up/down slop, also the pivot pin with the zirk fitting is worn and is a bit sloppy.

    After I get home, Ketchikan, I will correct all these issues. I think it will work well enough to not strand me en route.

    I will be vigilant and careful.

    Thanks again for the observations.

    Jim Dahl

  9. #9
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    "The clutch is good and engaged solidly. I rode the machine in traffic and as it got hotter and on the way home from 20 miles out, it gradually was dragging more and more then it finally would not dis-engage.."

    All the adjustment advice is good to know and use but if this is a new bike
    to you you should really take a look at the bearing between the rear end of
    the clutch actuating pushrod that passes through the transmission and the
    clutch actuating lever at the back of the transmission - the behavior you
    describe could be explained by this bearing going away - if this is the flat
    radial needle bearing type this failure is common - once the bearing is gone
    then the pushrod begins to bore a bigger dent/hole in the clutch at the front
    and the rod gets soft and shorter

    Remove the lever from the back of the trans - pull out the bearing - clean
    and grease all if no damage and know there is no problem here before spending more time and money on cables and adjustments. This is not a
    difficult task with transmission in place in the bike.

  10. #10
    Registered User skiteach's Avatar
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    Great point! Never thought of that one.
    '73 R75/5
    Never had a bad day skiing!

  11. #11
    moose738
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    Ditto on the bearing

    Good advice regarding the bearing. I experienced a 'frozen' bearing last year. It was installed incorrectly by the BMW shop after they rebuilt my transmission. This caused the bearing not to rotate. As noted earlier, this causes the pushrod and clutch plate to wear rapidly where they come in contact.

    If you pull in your clutch lever for an extended time, such as for a long stop light, the wear can be significant enough to greatly increase the clutch level adjustment in only that short time. That would be a good indicator of this type of problem. If this is what you are experiencing, you would not want to take a long trip without fixing the problem.

    But, if you take out the bearing and it looks fine, enjoy the trip!

    Regards, John

  12. #12
    Registered User gertiektn's Avatar
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    I will check this out. Thanks.

    more to follow..

  13. #13
    Registered User gertiektn's Avatar
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    I pulled it apart. Removed the lever, pin worn, pulled the bearing and facing items on both sides, badly worn. The small bearing race with needles falling out and looked seriously worn. The mating faces are grooved with appearant chatter wear.

    I have ordered the whole set from back to front as replacement parts. I think that I have id the reason the adjustment screw was all used up. The last piece that is called a pin, a felt, a washer, was as one piece that is solid with a pin at each end. I surmise that the part is the wrong part for this machine and shorter than stock. It worked but looks shorter than the stock parts.

    I ordered from BMW-Max out of NY. Hoping the parts arrive in time.

    I will let you what happens next...stay tuned..in the mean time I am off for a weeks ride to NM on a Yam 550 , twin, w/c,shaft drive,fully faired, Vision XZ.

    Thanks for the tips so far.

  14. #14
    beemerfield
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    I have used the adjustment procedure several times on all three of my bikes. It seems like there are some very small differences from bike to bike that you have to deal with. There must be a slight bit of wear in all of the parts that are affected that cause some minor differences that you just have to "feel". I seem to try and measure everything exactly, but still have a minor issue until I adjust a little further.

    Not sure that this makes sense, but when I try and "go by the book" exactly, I'm close, but not quite?

    Hope you get it the way you like it!
    beemerfield

  15. #15
    Registered User gertiektn's Avatar
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    Well, I got back to Denver and the parts were all there. I had to remove the shocks and pull loose the rear wheel to get the swing arm up high enough to use the flat spot made for that purpose, and was able to magnet the rod out. I replaced with all new parts. I had great difficulty fitting in the felt piece. After several attempts and great frustration, wondering why BMW had not fitted an O-ring here, I gave up.
    When I pulled the parts out there was no sign of this felt piece, and I had no time to deal with it.
    So all assembled and carefully greased, it wall slipped together and adjusted it to spec and now the clutch engages smoothly with a calibrated grip and works like a champ.
    I have successfully made it to Seattle and will be taking the Alaska Ferry on Friday for home. When I get home and over the winter, I plan to strip this machine down and give it a thorough going over. It performed with well enough to get here with no delays or major issues.. I need to rebuild the front forks and attend to some mechanical and cosmetic needs.

    Thanks all for the help and insights and follow future posts on my project work on Gertie.

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