R100/7 - gearbox doesn’t have a Neutral......but it once did

Discussion in 'Airheads' started by chomiczewski, Apr 1, 2018.

  1. chomiczewski

    chomiczewski Been here awhile

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    Yes, I missed that last one in the video. I went back and checked, it drops into 5th too.
    #21
  2. ME 109

    ME 109 Long timer

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    And beggin' yer pardon, toothies correct alignment.

    Hmmm, so what's not right to cause this......
    #22
  3. chomiczewski

    chomiczewski Been here awhile

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    I believe I torqued to 155 ft-lbs. I’ll be using the 140 and Loctite on the reassemble.
    #23
  4. tsADV

    tsADV Been here awhile

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    I still think it is odd you weren't able to put it into neutral, only due to the output flange being torqued up to spec.

    To me, it looks like your shifting mechanism is from a pre-75 gearbox - check the lower edge of the lower shifting cam, where the neutral switch plunger interacts with it. Anton has described the differences on his site, check the link I posted. If your switch fails, it will have to be replaced with one for a /5, not /7.

    Check the casting date on your box, and the serial number, to see if it all indicates a pre-75 manufacture date. Not sure if internal parts can be mixed between years and still work predictably.
    #24
  5. disston

    disston ShadeTreeExpert

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    Any of the three shifting mechanisms will work in any 5 speed gear box. The neutral light switch has to match the mechanism for the light to work properly. The neutral light switch does not effect anything else other than the working of the light.
    #25
  6. chomiczewski

    chomiczewski Been here awhile

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    The Mfg date is 09/78. S/N lookup puts a same date. I will read up on Anton’s description. Thanks!
    #26
  7. chomiczewski

    chomiczewski Been here awhile

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    Definitely works where te Neutral switch gets pushed in. The description on that site matches the pre 1976 version.
    #27
  8. AntonLargiader

    AntonLargiader Long timer

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    Does the output flange (or wheel, if the trans is still in the bike) turn easily in gears 2~5? Or is it stiff?

    EDIT: I mean before you loosened the output flange nut, so I guess I should ask DID it turn smoothly?
    #28
  9. Pokie

    Pokie Just plain Pokie.

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    If the output shaft won't turn after torqueing the flange, any chance it's binding on the seal? After market seals will often be wider than stock and will bind on the output flange, or if the stock seal isn't all the way home. If the shaft won't turn free, you WILL have trouble finding neutral or shifting in general.
    #29
  10. chomiczewski

    chomiczewski Been here awhile

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    No, it didn’t. Seemed like every gear was rough. I took off cover and checked everything, looks ok. I torqued to 140 ft-lbs with some blue loctite. Neutral is back and every gear is smooth.
    #30
  11. AntonLargiader

    AntonLargiader Long timer

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    If the tapers aren't clean and dry, you can actually stretch the flange over the shaft until it hits the rear bearing, locking 1st gear to the shaft. That will cause problems in everything but 1st gear.

    You'd think, looking at the very solid steel parts, that this isn't possible. It is. I've had tapers that I thought were clean but I could feel that it wasn't right when I tightened the nut because it never firmed up the way it should have and went too far. Pulled it apart, cleaned again, tightened right up like it was supposed to. Once you've done a few of them you know what is right and what isn't.
    #31