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Thread: Unexpected Neutral When Downshifting to First

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  1. #1
    professor
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    Question Unexpected Neutral When Downshifting to First

    On more than one occasion, I've been stopped at an intersection, light changes, start to go, but discover the bike (GTL) is in neutral. I down-shifted like I usually do, heard the clunk each time, but apparently either did not go into first gear with the last clunk or it slipped out. When that happens, I pull in the clutch, press down on the shift lever, hear that strong "clunk", and it usually goes into 1st, but sometimes it's still in neutral and has to be pressed again once or twice to get it into first. The dealer checked the linkage and says it's fine and most of the time there is no problem.

    On a 20 mile trip through numerous stoplights, I often make it home without a single malfunction, but some days it will happen two or three times. The record so far is seven failures to go into first during one trip home.

    I'm sure it is not my shifting technique, because I have ridden motorcycles for decades (including other Beemers - an RT and an LT) and have never had this happen. Anyone else have this experience? Any ideas?

  2. #2
    Registered User mneblett's Avatar
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    I'm not the only one!!

    I had this problem with two K16's. After a LOT of technique observation/modification, lever adjustments, tranny research, and general soul searching, I came to this conclusion:

    The transmission goes into neutral from 1st too easily, and my "normal" shift technique when stopping caused the tranny to pop into neutral.

    As I come to a stop, I tend to hold the shift lever down in 1st with my toe until it's time to put my foot down. When I do put the foot down, I don't lift my toe off the shift lever, I simply slide it laterally off the lever and extend to the ground. When my toe clears the lever, the return spring in the tranny returns the lever back to its rest position -- with enough strength that the momentum rolls the shift drum into neutral.

    This is consistently repeatable for me, and if I think about it and don't let the lever "pop" back up, it never goes into neutral.

    IMO, the issue is a design issue: either the return spring is too strong, or the cam between first and neutral on the shift drum is too shallow -- either way, there is not enough resistance built into the system to prevent the roller that follows the shift drum from over-topping the cam and allowing the tranny to shift itself as the lever returns to rest.

    Unless/until the return spring and/or the shift drum is modified by the Mothership, the only option for me is to train myself to not allow the lever to ever suddenly be released when in first to "pop" back up.
    Last edited by mneblett; 11-11-2012 at 01:26 PM.
    Mark Neblett
    Fairfax, VA
    #32806

  3. #3
    professor
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    Thank you so much!!! I think that might be what the problem is. I'll play with that idea when I'm riding today and see if that's it. As I review the times when this happens, I'm thinking that what you describe is exactly what is happening. I really appreciate your sharing your thoughts.

    Jim

  4. #4
    professor
    Guest
    Now Mark, just one other thing. Can you explain why the 1600's have two oil drain plugs? I'll be doing my first oil change soon and I don't think there will be a problem, but I can't find out why it is designed that way. Thanks.

  5. #5
    Registered User mneblett's Avatar
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    The K16 is a dry-sump motor. Unlike the previous wedge-K K12/K13 motors that had their oil reservoirs as separate tanks, the K16's dry sump reservoir is integrated into the engine -- part is at the right rear (where you add oil) and part is under the engine (the sump between the catalytic converters). The two reservoir portions communicate with one another, and therefore form essentially one tank.

    When you remove the first drain plug, you are draining the oil reservoir. When you remove the second plug you are getting any remaining oil in the dry sump under the crankshaft and gearbox, above the lower reservoir.
    Last edited by mneblett; 11-10-2012 at 02:10 PM.
    Mark Neblett
    Fairfax, VA
    #32806

  6. #6
    professor
    Guest
    Thanks, Mark. I knew I could count on you.

    I'm still not sure why the two tanks are better than one - since "The two reservoir portions communicate with one another, and therefore form essentially one tank." - but at least I know more than I did. I appreciate it.

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