Third gear issue 71 R75/5

Discussion in 'Airheads' started by n8mojo, Mar 26, 2012.

  1. n8mojo

    n8mojo Adventurer

    Joined:
    Nov 4, 2011
    Oddometer:
    76
    Location:
    Sacramento, CA
    Hey Old Cools, I have a question that maybe some folks that have been around the airhead transmissions for a while can help with.

    My '71 shifts great up and down from all gears, EXCEPT 2nd to 3rd. I'd say 75% of the time (perhaps less so when the bike is cold), the transmission doesn't engage very smoothly. It doesn't grind, but sort of rattles and I can feel in the shift lever. It's not super alarming or horrible sounding, but I want to make sure I'm not approaching some kind of failure.

    I changed the transmission oil recently, and noticed a decent dab of soft fuzz around the drain plug, but I don't know when the last change was. According to the last owner, and the odometer, the bike now has 30k. I replaced the oil with Valvoline 80w-90. I have not adjusted the clutch since I got the bike.

    I also noticed a description of a similar problem in the 5 united forums about 8 years ago here http://groups.yahoo.com/group/5united/message/22178. Both of his bikes were also '71.

    The bike stays in gear fine once there, and once in a while I get a nice clunk when shifting into 3rd, but nothing like the other gears. It's a bit unnerving and unsatisfying hitting 3rd, so I thought I'd check here.

    Nate
    #1
  2. Solo Lobo

    Solo Lobo airhead or nothing

    Joined:
    Mar 16, 2004
    Oddometer:
    9,701
    Location:
    Shoreline, WA
    Nate,

    The first (and cheapest) thing to do is to check that your clutch is adjusted in per the factory method to the factory specifications....
    #2
  3. supershaft

    supershaft because I can

    Joined:
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    9,116
    Location:
    San Francisco Bay area
    Chances are you need a new dog plate and your shifter fork adjusted.
    #3
  4. AntonLargiader

    AntonLargiader Long timer

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    Oddometer:
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    Location:
    Charlottesville, VA
    The 2-3 shift moves both forks, while the other shifts only move one. Normally this isn't even noticeable, but that might be at the root of the problem. If one of them (probably the 3-4 fork) is out of adjustment you'll get some difficulty.

    Unfortunately, the trans has to come apart for that to be adjusted.

    Does 4th seem to engage too eagerly?
    #4
  5. n8mojo

    n8mojo Adventurer

    Joined:
    Nov 4, 2011
    Oddometer:
    76
    Location:
    Sacramento, CA
    Got out for a good ride today, and noticed that if I preload the shifter it is much less likely to have difficulty engaging. Makes all gear shifts a bit smoother actually.

    I can't really say it's eager to get into 4th, If my memory is serving me correctly, it does seem 3rd requires a bit longer of a shift "throw" before engaging. Or perhaps it just feels that way because it's not that confident going in.

    Was actually hoping for an "oh ya, that's an airhead" but looks like I *might* have trouble on the way. I'm going to try to learn to shift it smoother and keep my eyes/ears on it. I've only had this bike since November.

    Nate
    #5
  6. Cam3512

    Cam3512 Cam from NJ

    Joined:
    Nov 11, 2010
    Oddometer:
    43
    Location:
    South Jersey
    My '71 does the EXACT same thing. I need to put some more "toe" into the 2-3 shift than the others, not always a smooth "clunk". No issues on down-shift.
    #6
  7. n8mojo

    n8mojo Adventurer

    Joined:
    Nov 4, 2011
    Oddometer:
    76
    Location:
    Sacramento, CA
    Well that makes 4 of us, if I count the guy that had the same problem on 2 of his '71s from 5united.
    #7
  8. n8mojo

    n8mojo Adventurer

    Joined:
    Nov 4, 2011
    Oddometer:
    76
    Location:
    Sacramento, CA
    I just finally learned to work around it by adjusting how I shift. If I'm careful, it engages perfectly. I guess every bike has it's personality and maybe we just need to work with their quirks. A blip, then release, then a quick shift up, a little voodoo, and it's all good :)

    Nate
    #8
  9. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
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    9,746
    Location:
    backwoods Alabama
    If it seems to rattle or clunk into 2nd or 3rd that may not be abnormal. Have you tried preloading the shift lever when you shift? I wouldn't worry about repairs til it starts jumping out of gear...

    --Bill
    #9