R1150GS 1999 Gearbox shift fork followers

Discussion in 'GS Boxers' started by Welshman, Dec 4, 2017.

  1. Welshman

    Welshman B.U.F.F.

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    Ok, so I have found out that the early 1999 R1150GS 6 speed boxes had shift drum issues 5th to 6th, I stripped my box in 2012 to replace the intermediate shaft bearings and it had shift drum damage, which I dressed out and it has survived until now, too few kms only about 35,000 since then.

    So it has started popping out of 5th again, so I have pulled the box.

    I have some shift drum damage, recognized will sort it.

    But what I also have, is that the shift fork followers have play in the follower bushes on two of the three forks, the manual doesn't give a tolerance or even mention it I would think it should be nil?
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  2. Steptoe

    Steptoe steptoe

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    Selector forks should have no play.
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  3. Welshman

    Welshman B.U.F.F.

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    I thought so Mr St Eptoe, are they pressed in as I assume? So I need to find a secondhand set of forks and a shift drum. :D Or can the pins be pressed out and replaced?
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  4. AntonLargiader

    AntonLargiader Long timer

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    You're talking about the rollers on the shift forks? I can measure a few and tell you how much play they have. A tiny bit isn't going to affect anything.

    I repair a good number of gearboxes and I've never seen a problem with the early ones. In service school they recommended replacing the selector pawl mechanism with the newer one any time a gearbox was open; maybe this is the root of your problem?
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  5. AntonLargiader

    AntonLargiader Long timer

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    I just checked a couple of shift forks and they have up to about 0.45mm end play on the roller but very little radial play. They are steel rollers on a steel pin so I don't see how you could really get any radial play there unless something else had gone really really wrong.

    The end play isn't going to hurt anything unless the peg is rubbing on the shift drum, which I've never seen.
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  6. Welshman

    Welshman B.U.F.F.

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    That is pretty much what I think I have, I have minimal end play but on 2 of the 3 I have radial play, but in the axis of the gearbox shafts only.
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  7. Beebop

    Beebop Adventurer

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    Not perhaps from riding with your foot on the shifter ?
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  8. Welshman

    Welshman B.U.F.F.

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    I thought that too, but that would show up as wear on the shift forks themselves. I am waiting for the parts, the guy I bought them from sent it Post Office not Postnet.
    #8