Airhead tranny problems, or is it normal?

Discussion in 'Old's Cool' started by mwells, Aug 18, 2006.

  1. mwells

    mwells Umm...Is this thing on?

    Joined:
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    On my new (to me) R100R, I am having trouble shifting down from second to first. It seems that when the clutch is all the way in, it is reluctant to get into first, but if I let the clutch out a fraction it will shift down. Only happens (from what I can tell) when getting into first (either from neutral or second), and it probably is an issue 60% of the time. Maybe 5-10% of the time I have serious trouble getting into first, and have to play with it.

    Since I am coming to a stop anyway, it usually isn't an issue. I am just worried about it being indicative of something more.

    So - Normal or something to worry about?

    Matt

    PS - Love the bike, if I can get this and the squealing brakes sorted out (I think new pads were just put on) I will be extremely happy.
    #1
  2. Bigger Al

    Bigger Al Still a stupid tire guy Supporter

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    Sounds like it might be time to lube the input splines on the tranny. It's not a really hard job, but it pays to have experienced friends around who will help out for food and beer. www.airheads.org has a nice technical area, and link to Bob Fleischer's (AKA Snowbum) site. Tons and tons of very helpful info there, but a bit verbose at times.
    #2
  3. BareRider

    BareRider Adventurer

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    You might want to make sure your clutch is adjusted properly. There's lots of tech articles about how to do this. If it isn't adjusted correctly you will have problems going into first when it's hot like after a long highway run.

    Good luck, richard
    #3
  4. jtwind

    jtwind Wisconsin Airhead

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    A spline lube is something to do if you don't know if it's been done on your bike or it's been 12-15 thousand miles since the last one. Spline lubes are not difficult, usually around 2-3 hours.

    Every airhead I have owned sometimes has had minor difficulty going from neutral to first when not rolling. Usually they won't quite go into first and I let the clutch out slightly and they will go in. This is with recent spline lube or not. If yours is more than that it needs to be looked into. JT
    #4
  5. Spanish Bob

    Spanish Bob I dont know where I am.

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    do what has been suggested here. I dont think it is anything serious and the terminal gearbox issues I have had have been associated with unpleasant noises.
    #5
  6. mwells

    mwells Umm...Is this thing on?

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    That is what I figured. Just wanted to see if I was overlooking some 15 minute problem by thinking only about the 3 hour long problem (which have have done before and usually realize about 2 hours into a project when then engine is in pieces across my garage floor). I guess I know what my Sunday will be like.

    When out trying to diagnose the problem yesterday, when I was concentrating on 'what exactly happens to make shifting hard' I also noticed that I could 'feel' the transmission shaking through the shift lever when shifting down (it only happened when I shifted slowly, and I only did then when trying to concentrate on finding the problem).
    #6
  7. dfc

    dfc nonattractive

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    Mine sometimes makes "I wont go there" crunchy noises going from 3rd to 2nd, hard to get into 1st as well.
    Its properly shimmed, has the circlip,recent spline and clutch lube as well and has never found to be graceful in any respect. Have you ever seen the gears in an airhead tranny?. There is a reason they shift like a tractor.

    In other words

    TADT

    :wink:
    #7
  8. Mugwest

    Mugwest "You mean the REAL world!?"

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    FYI to airhead noobs: airhead shifting is a constantly modifying technique. Not every technique will work every day-- i've never ridden a bike w/ a 'fresh' box, the closest to new i ever rode had 30K miles on it (R65) and that was notchy but tight, like new, i'd guess. The '77 RS gathered 50K miles before i sold it, and was a constant art-quest in shifting: with the right amount of preload on the clutch lever (and warm oil) it could shift like buttah. At other times (also w/ warm oil) a shift would seem like there was a monkey wrench running around in there. But it was all in the rider, alas.

    The 81' G/S (>60k) box i just pulled is the same, but much easier to modulate due to the lighter clutch gear of the post 81 models. By now i have enough experience with it to usually get the buttah-shift. Usually! Not always.

    There are a bunch of rider-input dynamics that directly affect shifting: timing the clutch pull, how fast you pop your foot up (for an upshift), how big yr boots are etc. That last factor is significant-- with my big Disco boots there is not much clearance tween my toe and the tip of the shift lever-- my foot input is thus much reduced. This is glaringly apparent when i (rarely) wear a less bulky boot-- i have to move my foot up quite a bit more to effect the same shift speed i'm used to. These things are also adjustable, if you have the threaded shaft w/ ball joints connecting yr foot shift lever w/ the gearbox shift shaft.

    Bottom line: provided the box is healthy, yr shifting is largely a timing issue: hand and foot. May you have many happy miles learning to perfect yr shift technique

    I'm weird but i actually like that about airheads-- the constant learning of feel for the machine. If you keep water out of the oil (speedo cable boot) these boxes are very tough.

    lube yr splines, keep the clutch cable adjusted (at hand lever and throwout lever--see manuals), change yr oil a couple times a year, and keep the speedo cable boot sealed. You'll be fine
    #8
    quietglow likes this.
  9. Troutrider

    Troutrider Vicarious Adventurer

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    The first airhead I ever rode was my brother's '81 RT. Going from second to first it absolutely would not go unless you blipped the throttle a little. He didn't tell me this and I almost bent the lever trying to downshift. My '77 makes all sorts of racket if I blip the throttle but is almost smooth if I back off and stay off the gas while downshifting. It also doesn't want to go into first from neutral when cold. I let out the clutch and pull it back in and all is well. My other airheads were all different as well. Seems like every one has some different quirks that make it work. All my old Volkswagons were the same way. You just have to try a little bit of everything and see what works. Good luck. Most all of them still sound like a box of rocks when shifting. Just part of the personality we know and love.

    Troutrider
    #9
  10. Middleweightboxer

    Middleweightboxer Middleweightboxer

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    First - Perform a spline lube, dry splines make downshifting harder and more metalic. Then see what happens. Use a proper lube like Wurth SIG3000 that will stay in place. Honda lube won't.

    If the spline lube doesn't help then your first gear may have worn a little too much allowing it to misallign slightly preventing the dogs from sliping into place until the clutch spins the assembly on engagement. My trans had this exact problem with 5th gear. A new gear with ever so slightly tighter fit solved the problem. Or there is a bearing that is going bad and allowing the misallignment. Watch for metal bits in the oil.

    If you have a transmission that has shifting problems, don't work around them or live with them, fix it. Otherwise sooner or later you will end up on the side of the road with a trashed transmission.
    #10
  11. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Truth of the matter is that these trannys are fairly crudely machined. The dogs, along with their mating holes, aren't evenly spaced and only two or three wind up taking the load. HPN offers a service to detail the trans, and one of the things they do is make the dogs and their holes uniform. That's a good part of where the metal in the trans comes from - bits of metal wearing from the dogs. You want to keep those filings from getting into the bearings and destroying them.
    #11
  12. camgregus

    camgregus riding gently now Supporter

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    Mine never goes into first without letting out the clutch then pulling it back then shifting down. Then clunk.

    Now I feel better. I thought I needed a new tranny or a re bearing and lube. Maybe I'll just re lube it. I think it shifts better with synthetic. It leaks more though.
    #12
  13. Wirespokes

    Wirespokes Beemerholics Anonymous

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    I don't use engine braking, but shifting down for more torque - yes. That sort of down shifting hasn't been a problem for me, though getting it into first at a stop light is just like you say - let the clutch out part way, roll it a few inches and it goes in. Normal.

    I learned how to shift these things fifteen years ago on my first bmw, a '76 R90/6. Those were harder to shift because of the heavy flywheels and the different rear suspension. Mine was extremely hard to shift due to needing a proper shim job. It took me a couple years before I could shift and down shift it without a loud clunk or grinding about 80% of the time.

    Just recently I tore into it and discovered someone else had been in there before me and shimmed it with ten times too much play. :eek1 NO WONDER IT WAS A BITCH TO SHIFT!!! Now it works like it's supposed to.

    The other side of the coin is that every other beemer I've ridden in that time shifted great! Well, of course! Look what I had to compare it to!!! :lol3
    #13
  14. sharkey

    sharkey XLV750R

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    They don't shift like anything else (except maybe Guzzis) because there's no primary reduction, so the clutch and input shaft are spinning 3 times as fast as on most Japanese bikes. But with good trans oil, good spline lube and good technique they're okay. Check for metal in trans oil.

    Mine sometimes has two third gears when shifting up ...

    -----sharks
    #14
  15. Joerg

    Joerg Long timer

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    Well, from what I read here it seems that most airhead owners have a badly adjusted clutch :lol3

    I would suggest to do three things:

    * adjust the clutch, exactly as explained in the user's manual.
    * I don't recall the R100R switch mechanism exactly, but if it's like the GS you may want to take the two ball joints off, clean the whole thing and grease it thoroughly.
    * check if the gear switch lever is adjusted very low. If this is the case, it may hit the exhaust collector box upon downshifting, thus preventing the correct gear change.
    #15
  16. mwells

    mwells Umm...Is this thing on?

    Joined:
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    Shift lever is high (anything that can fit my boot under it without me having to work for it is high).

    I will do the lube this weekend. If nothing else, it will be fun taking the bike apart for the first time.

    I will also check out the clutch and shift lever. Can't hurt.

    I will report back post-lube.
    Matt
    #16
  17. dfc

    dfc nonattractive

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    Well mine shifts all right, now that I've learned to adjust clutch/shifting habits from any other bike I've ever ridden. You say to adjust the clutch as it says in the "owners manual". I would assume most owners are like me, and do not have the original owners manual. We have the Clymers or Hanes. My Clymer talks about setting free play and making sure the clutch fully engages and fully disengages, is there anything more than that? pray tell.
    :ear
    #17
  18. Joerg

    Joerg Long timer

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    Sorry - I thought it would be "general knowledge". BTW, not having the standard manual is a pity ... in contrast to japanese motorcycles, this one tells you quite a lot about maintenance procedures, torque values etc. Together with the complete stock toolset, it is one of the things that I would "like to have" if I buy a secondhand bike.

    I don't know Clymers or Hanes since I'm using the BMW factory manual (which is, btw, available as a regular part from BMW. Cost in Europe ~50 €, but well worth the money).

    Short description, valid for all 2V airheads from 1981 onwards:

    Note: I'll call the two clutch levers the "clutch lever at handlebar" (German: Handhebel) and the "clutch lever at gearbox" (German: Ausrückhebel). The latter is the huge lever that is located behind the gearbox but I don't know its correct translation in English, sorry ;-)

    1. Use the adjuster of the clutch lever at the handlebar (!) to adjust the clutch lever at the rear of the gearbox, so that the distance from the clutch lever at the rear of the gearbox to its counterpart (i.e. the thing where the clutch cable is attached on the engine side of the gearbox flange) is 201 mm + 1 mm.

    2. Use the adjuster screw of the clutch lever at the rear of the gearbox (!) to adjust the clutch lever at the handlebar. The desired play is 2 mm +/- 0,5mm.

    That's it. What seems to confuse many is that you use the adjuster at the "other end" of the cable each time ... anyway, if the clutch is adjusted this way (and your gearbox is shimmed properly and the switch mechanism ios greased), gear changes should go smooth ...

    HTH!
    #18