1987 R100S stuck in gear.

Discussion in 'Airheads' started by aeholton, Jan 5, 2013.

  1. aeholton

    aeholton R100S

    Joined:
    Sep 18, 2005
    Oddometer:
    61
    Location:
    Tampa Bay Area
    I had T1-C7 neck fusion surgery back in July. Since then I have been riding our Aprilia SportCity scooters. I've been backing the airhead out of the garage and starting in the driveway every couple of weeks. I took it for a short ride a couple of months ago, but only got a few miles and had some neck pain, so I came home.

    Today I decided to give it another go and headed out on a ride. I was a few miles from home and went to up shift after downshifting for a car turning in front of me but I couldn't get it to change gear. I slowed down and tried downshifting and no luck there either. I returned home. The transmission is stuck in 2nd or 3rd gear. The shift lever turns the shaft going into the transmission but no clicks. Any ideas what the problem is and fixing solutions? Did I cause this by not riding for the past 6 months?
    #1
  2. elmontanero

    elmontanero Practicing...

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    Had that happen to me... Pawl spring is usually the culprit. Had nothing to do with the rest the bike had.
    [​IMG]

    Number 7 in the pic... has to be opened up to get to it.
    Mine went to the rebuilders... at 50k it was time enough to get it rebuilt.
    #2
  3. disston

    disston ShadeTreeExpert

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    +1

    Sure sounds like a pawl spring. Don't know of any other cause for this except the bolt that holds the shift lever in the trans is loose and it sounds like you checked that.

    You did not cause this by not riding.

    Since the repair is a disassembly of the trans most will opt to have the whole thing done anyway. Some riders will do the R&R and send the trans off for repair. If you think you could do this yourself at some later time there is no penalty for putting it off till you can do the work. How many miles on the trans?
    #3
  4. aeholton

    aeholton R100S

    Joined:
    Sep 18, 2005
    Oddometer:
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    Location:
    Tampa Bay Area
    Bike has 60k miles. How difficult is it to remove the transmission? Any special tools required for removal? I would probably send it off for rebuild or try to find someone local that could do it for me. I think doing a transmission freshening is beyond my capabilities.
    #4
  5. disston

    disston ShadeTreeExpert

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    You need a 10mm box end wrench to take the bolts off the drive shaft. A turned down 27mm socket or the special tool kit socket wrench to disco the swing arm.

    It is advisable to check the condition of the clutch and the rear engine seal while the trans is off getting rebuilt. There are several tools needed for taking the clutch off and installing a new seal. You probably don't have any clutch symptoms and if there is no oil on the shelf under the trans some will opt to leave this stuff alone.

    If you are going as far as replacing the rear engine seal a torque wrench will be needed to put the flywheel back on.

    It all ads up if you get every special tool called for. Some of them are needed and some you can work around.

    Taking into consideration the neck injury you are recovering from the trans weights a little more than 50 lbs ( I think) and it has to be lifted and held in front of you. Many of us need a helper even if not injured.
    #5
  6. georgesgiralt

    georgesgiralt Been here awhile

    Joined:
    Aug 12, 2012
    Oddometer:
    141
    Hello !
    I did this a couple of weeks ago on my R65. The same spring died on me when breaking the bike in after piston rings change and clutch renovation...
    When doing the clutch I removed the swingarm. Then when removing the gearbox to change the broken spring, I decided to try the method BMW advertise for post 1982 models : Leave the swingarm untouched but advance the engine in the frame. Lots easier !
    You have to get an hydraulic jack or something equivalent, to put under the oil pan to get the engine weight.
    First removve the airbox, battery and battery case, left foot rest , left carb. Disassemble the liaison between the mufflers and exhaust pipes. remove the clutch lever and cable and the actuation boot (beware there is a spring under it)
    Remove the final drive boot and undo the four 12 sides screws.
    Then whit the engine on the jack, remove the engines bolts on the frame and the two mounting studs. Using the exhaut pipes, pull the engine as far as it will go to the front.
    Remove the bolting bits between the tranny and the engine case, pull the gearbox to the swingarm and using a pair of pliers, pull the clutch pin out of the clutch and into the gearbox. Once cleared, rotate the box to undo the neutral switch wires, and remove the box from the left.
    It is as easy than that !
    Assembling back is a walk in a park as you do not have to align the swingarm back and no need for the special machined 27 mm socket !
    #6
  7. aeholton

    aeholton R100S

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    Thanks. I think I may have to just open up the wallet and find someone local to do the entire job. :cry
    #7
  8. disston

    disston ShadeTreeExpert

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    I don't know if the alternative method George talks about is really all that common. Do you later model guys do this? It actually sounds to me like more hassle than removing the swing arm. It is not a problem to center the swing arm when reinstalling, do it with your good eye. Taking the swing arm off also means the bearings get cleaned and greased.
    #8
  9. ritetwist

    ritetwist Been here awhile

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    I'm with you Disston.Less bolts and lining up.
    #9
  10. ME 109

    ME 109 Long timer

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    Why take the swing arm off?

    Just take out the two swing arm pins, disconnect the brake caliper brace and pull the swing arm backwards.
    Exhaust stays put. Rear wheel stays put.
    Some folk might just remove one swing arm pin?
    #10
  11. disston

    disston ShadeTreeExpert

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    I tried to do this job once by leaving the final drive bolted to the swing arm. That makes it really hard to put everything back together. Just better all around if everything comes off one piece at a time and back on the same way. I no longer believe in short cuts. They end up causing more trouble.

    When I was younger I could do a lot of things I differently.

    I think I did hear once about somebody doing this job the way George describes it. I guess it can be done that way. I just don't see any advantage.

    EDIT; Oh.But ME 109 might have something. Don't remove swing arm, but move it back an inch or two. I think that way is common.
    #11
  12. chollo9

    chollo9 Screwed the Pooch

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    No offense, but there's no way it's easier to remove all that stuff and move the engine forward than either of the two swingarm "removal" methods. With a drum brake bike I can have a gearbox out in 30 minutes with no air tools and no lift. Wearing a clean white shirt. While talking to my neighbor. But my broom is upside down.
    #12
  13. ME 109

    ME 109 Long timer

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    Takes me 45 minutes with a disc brake bike, but I talk to myself.:freaky
    What's the difference between a disc and drum anyhowz?
    I disconnect the caliper arm, 30 sec.
    You disconnect the connecting rod. 30 secs ?
    #13
  14. boxerboy81

    boxerboy81 Stay Horizontal

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    Honestly, it's not that hard. A quiet 2 hours in the shed, taking your time and doing it step x step..20 steps to trannie outing...

    http://jhau.maliwi.de/mot/r100tic.html#gearbox

    Less than an hour the second time, but that won't be needed hopefully. Have a crack. You'll need a cheap socket to grind thinner for the swingarm bolts...see Disston's response above.
    #14
  15. LBourque

    LBourque G/S nut

    Joined:
    Nov 2, 2010
    Oddometer:
    233
    Location:
    Northern AZ
    I am currently doing the same job as you will have to do. PM me if you need to.
    #15