Transmission swap questions 1100GS

Discussion in 'GS Boxers' started by Uncledeadly, Jan 7, 2013.

  1. Uncledeadly

    Uncledeadly Been here awhile

    Joined:
    Oct 31, 2006
    Oddometer:
    169
    Location:
    BC, Canada
    The rear bearing on the input shaft let go on a trip last summer and I'm finally getting around to getting that bike rolling again. M97 transmission, 3/97 stamped on the steering head of the bike.

    I tore the transmission out and split the case, found that the bearing let go, heated up and spun the rear seal on it's bore and on the end of the input shaft (bore looks OK, shaft is toast!). When it heated up it made a molten mess of the pushrod piston assy. and oil migrated up the shaft, contaminating the clutch friction plate.

    I found a great looking used input shaft assy from a 95 RS (M94) and was planning on rebuilding the existing transmission until somebody suggested trying to find a good used box.

    New plan. I found a good looking used box from a 98 RT that came with the pushrod assy. splines and seals look great.

    Some questions have arisen after reading and research and I'm looking for some good input and advice from somebody who has maybe "been there and done that".

    1. I have no complaints with how the OEM clutch was working but if there is something better that doesn't break the bank, I am all ears. ( not really into the VW option though :)) I am , at this point, hoping to change only the friction plate but will see what the pressure plates look like when I take them apart tonight.

    2. I have read where some guys are changing up the clutch spring with an 1150 spring (stronger?). Is this the only thing that needs changing, and is it a straight over swap with my existing spring (mfg 3/97)?

    3. I believe that there was a clutch upgrade in , around 12/97 as I have seen clutch parts listed pre 12/97 and post 12/97. What was changed and will the "post 12/97" RT pushrod assy be compatible with my existing clutch assy?

    Looking forward to hearing what you have to say
    Thanks
    RR
    #1
  2. Uncledeadly

    Uncledeadly Been here awhile

    Joined:
    Oct 31, 2006
    Oddometer:
    169
    Location:
    BC, Canada
    Has anyone have any real experience with the Siebenrock oil proof clutch plate?.....all of the threads on this have ended without any real ending....if you know what I mean....:lol3
    #2
  3. vintagerider

    vintagerider Long timer

    Joined:
    Nov 20, 2005
    Oddometer:
    1,976
    Location:
    the west
    Bump for you. Are the two push rods the same length? L=258 mm in the fiche. Did not know that the 5 speed could contaminate the clutch similar to the way that the 6 speed does when its control slave fails. Same result just diff reasons for the rear input shaft seal failing. Anybody else know about the upgrading the the 1100 clutch with 1150 diaphragm spring?

    Check the box mounted clutch lever carefully for hairline cracks. Clean and lube the 12x18x16 needle bearings. I've had two of those levers snap. Carry a spare.
    #3
  4. Uncledeadly

    Uncledeadly Been here awhile

    Joined:
    Oct 31, 2006
    Oddometer:
    169
    Location:
    BC, Canada
    I found the answer to my clutch plate question (what changed in 12/97)....Service Bulletin 2818 dated 04-14-98.
    - The RT and GS pushrods should be same (same part number.)
    - I ended up going with a siebenrock basic friction plate and upgrade the entire clutch pack with the post 12/97 version and am going to use an 1100 spring as I had no problems with it prior to this issue.

    Hopefully parts will arrive soon and I can get the bike rolling again!:D

    Thanks for the bump
    RR

    Topic: ​
    New Clutch Parts

    Details: ​
    All R 850/R 1100 and K 1200 RS models produced from December 1997
    have received a new clutch disc, manufactured by VALEO, and a
    new pressure plate (see applicable part numbers below).
    Earlier production for both series can be fitted with the new parts.
    However, due to changes in specifications (a thicker pressure
    plate, a thinner clutch disc), the new VALEO clutch disc is not
    compatible with the old pressure plate.
    In this application, the
    new clutch disc and pressure plate must be replaced as a
    pair.
    Series
    Production:

    R 850/R1100 models: Starting with December 1997 production.
    K 1200 RS: Starting with December 1997 production.​
    Part Number: ​
    R 850/R1100 Models: VALEO Clutch Disc: 21 21 2 325 864

    Used only in conjunction with ​
    Pressure Plate: 21 21 2 325 863
    R 850/R1100 models: VALEO Clutch Disc with reduced play
    on gearbox input shaft (KD - Scheibe): 21 21 2 325 862

    Used only in conjunction with ​
    Pressure Plate: 21 21 2 325 863
    K 1200 RS: VALEO Clutch Disc: 21 21 2 332 973

    Used only in conjunction with ​
    Pressure Plate: 21 21 2 332 974

    Attention: ​
    For R 850/R1100 and K 1200 RS models with production dates of 12/97 and
    later, all clutch parts can be replaced individually, as the new pressure plate
    will already be installed.
    On earlier production examples, installing the new VALEO clutch disc without
    replacing the pressure plate will not allow the clutch to completely

    disengage.
    #4
  5. Shango

    Shango Hi

    Joined:
    Apr 18, 2012
    Oddometer:
    52
    Location:
    Atlanta
    I put the 1150 spring in my '98GS. It's not noticeably stiffer at the lever and works great!
    #5
  6. MsLizVt

    MsLizVt pfft ...

    Joined:
    Jun 2, 2007
    Oddometer:
    1,627
    Location:
    Killington, Vermont
    UncleDeadly, hi!

    How are you making out?

    Thanks,



    Liz
    #6
  7. Uncledeadly

    Uncledeadly Been here awhile

    Joined:
    Oct 31, 2006
    Oddometer:
    169
    Location:
    BC, Canada

    It's coming along nicely, Thanks. Got a little sidetracked lately with a few other non related projects but should be back running by the end of the week. Got a little sidetracked polishing the muffler and cat lol. put your mind to it and that stainless shines better than the chrome shrouds! Brown stains gone and nothing but gleam! Looks a little out of place but what the hell!:D
    #7