GS100PD Clutch help

Discussion in 'Old's Cool' started by boxertwinuk, Feb 19, 2007.

  1. boxertwinuk

    boxertwinuk GB Rider

    Joined:
    Jun 3, 2006
    Oddometer:
    280
    Location:
    Engerland
    Hi guys, hope someone can help...I rode my PD in this morning to work. The clutch was fine on the highway, but when I got into heavy traffic in central london, it became totally unresponsive with no bite whatsoever. I adjusted the cable at the side of the road, till I got some bite, but whilst the engine was switched off for a few minutes it seemed to go back to normal and my adjustments meant that the cable was too tight and had to readjust again. This happened three times until I got into work...

    It also feels like the clutch might just be beginning to slip, but I'm unsure- under heavy acceleration it feels like the clutch is pulled in...
    #1
  2. Joerg

    Joerg Long timer

    Joined:
    Jul 10, 2001
    Oddometer:
    1,356
    Location:
    Lausanne, Switzerland
    Hi,
    You are very, very probably encountering a problem that seems to haunt all 2V GS models sooner or later: The piston of the clutch mechanism has swollen and is stuck in its guide of the gearbox housing.

    If the have a mechanical workshop, the fix is easy: Just take off the clutch lever at the rear end of the gearbox, and withdraw the rubber cap. Under this cap you will find a spring and a cylindric device that can be withdrawn with a pair of tweezers (yes, it's a bit of fiddling). This device is the infamous piston. The outer diameter of this piston must be at least 28.60 mm and at maximum 28.75 mm. You can either buy a new part (about 35 €), or simply have it machined down to 28.60 mm (which is what I did). Re-install everything, and your clutch will be fine again.

    On my GS, this happened after more than 120 Mm during a sunday afternoon ride. I don't know why this piston starts to swell after 14 years, but at least the fix was easy.

    Full text: http://homepage.sunrise.ch/mysunrise/joerg.hau/mot/r80gs.htm#slipclutch

    [​IMG]
    #2
  3. AntonLargiader

    AntonLargiader Long timer

    Joined:
    Aug 28, 2003
    Oddometer:
    4,349
    Location:
    Charlottesville, VA
    When the Airhead clutches get really hot they tighten up (the free play goes away so the cables need to be loosened). So if this is happening to you while riding along, it might have been slipping a little from either wear or misadjustment.

    Do a fresh cable adjustment with the bike cold and tell us which way you had to change things:

    1) Set the cable adjuster (at the handgrip) to show 201mm of exposed cable between the end of the cable housing and the front of the clutch arm. If some of the teflon liner is protruding it counts as cable.

    2) Set the clutch arm adjuster (in back of the tranny) to yield about 2mm gap at the handgrip lever.

    3) Squeeze the clutch and see how much friction there is. Replace the cable if needed. Compare to a few similar bikes if possible; it's really easy to forget what it's supposed to feel like.

    If the clutch slips under normal riding once it's adjusted this way, it might just need replacing.
    #3
  4. boxertwinuk

    boxertwinuk GB Rider

    Joined:
    Jun 3, 2006
    Oddometer:
    280
    Location:
    Engerland
    Thanks chaps, looks like I'll have to investigate further at lunchtime.
    #4
  5. boxertwinuk

    boxertwinuk GB Rider

    Joined:
    Jun 3, 2006
    Oddometer:
    280
    Location:
    Engerland
    Got the little piston replaced last night....20 minutes to get it off ...another 3 hours trying to get the new one back on...not much space there to manouvere..!

    Finally got the rubber gaitor back on but I couldn't tighten the clip around it. Too little space to get my fingers in...will try again tonight...

    any tips appreciated...!
    #5
  6. Joerg

    Joerg Long timer

    Joined:
    Jul 10, 2001
    Oddometer:
    1,356
    Location:
    Lausanne, Switzerland
    1. Get enough light.
    2. Ask someone to assist you (e.g. pulling the clutch in, which compresses the rubber gaitor).
    3. Ask someone with smaller fingers to do it for you.
    4. Grow a third arm (that comes in handy at many occasions anyway :lol3).

    Sorry, but that's all there is ... no secret involved, it's just weird to do it since one seem to need at least three hands. Or sufficient tools to hold things in place.
    #6
  7. boxertwinuk

    boxertwinuk GB Rider

    Joined:
    Jun 3, 2006
    Oddometer:
    280
    Location:
    Engerland
    Thanks, I'll try with the clutch in...didn't do that...!
    #7