Airhead Gearbox foamin' up!

Discussion in 'Airheads' started by Ray Ray, Dec 6, 2004.

  1. Ray Ray

    Ray Ray Adventurer

    Joined:
    Oct 31, 2004
    Oddometer:
    65
    Location:
    car drivers can't see at all, washington
    I was just out changing my hypoid oil in the '78 /7. lo and behol' the oil is like runny cake batter, yellow custurd, dripping from a dead dog's eye.
    This is the second time I have seen it this way. Last change was....oh...2000 miles ago?

    Details in the case:

    Bike lives in the PNW
    Lives outside (covered by bike cover)
    Gets ridden every work week 22 miles round trip and assorted jaunts on weekends (thats probably 250 miles per week avg.)
    Run BMW (made by spectro) 75-140 super synth
    Bike is a pisces
    Loves long walks and movies
    College education a plus
    Turn offs include, going slow, bad car drivers, 87 octane fuel

    So if anyone has any ideas comments or would like to get to know miss /7 please reply
    #1
  2. Chopperman

    Chopperman I am dead

    Joined:
    Sep 17, 2001
    Oddometer:
    27,033
    THis happens when moisture gets introduced or condenses in the oil. The speedo drive on an airhead is not sealed. And even if it were, it only takes a little bit. you will probably see the same in the valve covers if the bike doesnt get more than a commute to work and back in the winter.

    drain it good. put some inexpensive gear oil in there. Run it for a few hundred miles, replace it again.

    also put a little silicone sealer around the top of the boot that surrounds the end of the speedo cable. If the boot is cracked, replace it. Same goes for the cable outer sheath.
    #2
  3. Frank Warner

    Frank Warner Traveller

    Joined:
    Mar 14, 2002
    Oddometer:
    6,593
    Location:
    Sydney, Australia
    As chop says - water in oil.

    When you say second time you have seen it this way - when (as in time wise) was the first time you saw it this way? If it is just recently then you have a new leak for the water to get in. If it was a long time ago then may be you are just doing short trips at the moment and not getting the oil hot enough to boil off the water?
    #3
  4. Ray Ray

    Ray Ray Adventurer

    Joined:
    Oct 31, 2004
    Oddometer:
    65
    Location:
    car drivers can't see at all, washington
    OH, YEAH!!!

    That the boot is a little knackered so moisture is probably seeping in...guess I'll go get a damn boot.

    Thanks chopperman...you ever take a break, get a sandwich or something, maybe go to costco a buy some muffins.

    those muffins are good.
    #4
  5. Ray Ray

    Ray Ray Adventurer

    Joined:
    Oct 31, 2004
    Oddometer:
    65
    Location:
    car drivers can't see at all, washington
    uh yeah, It was about 2000 miles ago. "I do say this oil looks might watery, what thouest I doest, I will replace it"

    Today It was back. So I think Chopper be correct about the boot...ya ever notice it's always the boot why just last week I said look at that boot. Better do something about that boot, yup. BOOT BOOT BOOT...BOOT...and more BOOTS.
    #5
  6. Malindi

    Malindi Zen Adventurer

    Joined:
    Jul 9, 2001
    Oddometer:
    5,425
    Location:
    Vancouver, BC
    A new boot alone won't fix it. Put a tad of silicone on the area where the cable comes out the boot. That will seal it better. As well, it takes a few "cycles" to get the oil to not turn coffee color between changes. If you can, change with cheaper oil, run it around the block, change it, run it around the block etc. Do this two or three times to get all the water out, then replace with new expensive oil. Check again in 2000 miles etc. It happens to the final drives too on occasion.
    #6
  7. Wirespokes

    Wirespokes Beemerholics Anonymous

    Joined:
    Jul 26, 2002
    Oddometer:
    8,323
    Location:
    Jackson's Bottom Oregon
    I've heard of using marine outboard lower unit oil. I've heard stories of outdrives going years and years without an oil change and the gears looking like new. The oil evidently keeps the water in suspension, but doesn't allow it to rust the gears somehow.

    I've also heard that Caterpillar sells a gear oil that may be very similar and prevents water from building up in the bottom and rusting out the bearings, etc.
    #7