1977 R100RS shift shaft oil leak...

Discussion in 'Old's Cool' started by Sniper X, Sep 7, 2011.

  1. Sniper X

    Sniper X De Oppresso Liber

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    My RS just started leaking a tad from the shift shaft. It is a small puddle of about 2in in daimeter and it seems to stop after it cools from a ride. Stupid wuestion, but what goes in the trans for lube and where does it go in and where do I check it? I can't find a fill hole??!!??!?!?
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  2. airheadDavey

    airheadDavey Adventurer

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    Make sure the bike is on the center stand. The fill plug is located on the transmission and requires (90w syncromesh gear lube) right near the connecting rod for the shif lever and uses a 6mm hex key if I remember correctly. Remove the fill plug and use a piece of fuel line to attatch to the tip of the gear lube bottle to get the angle. Fill until fluid starts drizzling out the fill plug hole.
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  3. Sniper X

    Sniper X De Oppresso Liber

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    Damn, I knew that had to be it right after I posted this! THANKS! I'll go tot he parts sto and get some 90wt gear lube for lunch and fillerup before I ride home. Already ordered the new seal about twenty minutes ago for the shaft...2 in fact in case I bung one up the first time!
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  4. airheadDavey

    airheadDavey Adventurer

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    Double check to make sure its sycromesh that is needed. It might be hypoid as I cannot be sure. I get a gear oil that is approved for both syncro and hypoid.
    #4
  5. wirewrkr

    wirewrkr the thread-killer

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    ???? Synchromesh????
    That ain't no synchromesh box.
    You just need GL-5 Spec gear oil 80-90 wt is the most common.
    As long as it's rated "GL5" you're fine.
    8mm hex key, not 6
    #5
  6. kbasa

    kbasa Roubaix! Super Moderator

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    Replace the seal, then top off.

    To get the seal out, take the shifter off the trans, then take a ballpoint pen and lever the old one out. You should be able to press the new one in with your fingers. I can't remember, but I think the seal is set down in the recess a bit, so use the old seal to set it in there nice and square. :freaky
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  7. disston

    disston ShadeTreeExpert

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    I replaced mine a month ago. Because I'm supposed to know, I didn't ask for any advice. Well it doesn't leak at least. I had no problem getting the old one out. I used a most efficient method to install the new seal. I found a socket from a socket set. One that was large enough to drive the seal but small enough to not stick in the bore. Drive away. It went in so smoothly almost no effort. I drove it ALL the way in. Uh-Oh. The bore is much deeper than it needs to be. The seal is now almost not visible. Replaced the shift lever and topped off oil. Well it doesn't leak but if I have to do it again I think it'll be much harder to get the seal out. It's pretty deep. So let my mistake be a lesson for you and when you put your new seal in don't drive it all the way in. You can stop after it clears the edge 1 or 2 mm.
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  8. Sniper X

    Sniper X De Oppresso Liber

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    cool! They sould be here Tuesday. I did drain and change the hypoid with 80-90 when Alejo and I got back from the install at 17:30 in front of the shop. Busy busy so am glad I don't HAVE to swap the seal till Tuesday! The stuff that came out was like a melted cafe latte'. But there appeared to be no water in it. Is there a way for water to get in there, like a breather? It was pouring on me on the way home three times last week and once this week so I would not be sur[irsed it there is a breather that some water got in there.
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  9. Rucksta

    Rucksta SS Blowhard

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    The rubber boot on the speedo drive is the most common water entry point for the gearbox.
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  10. boxerboy81

    boxerboy81 Stay Horizontal

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    Usually no need to drain the oil to change the seal.

    Lean the bike on the right rocker cover/pannier, maybe on a step or an embankment or something. Remove the lever and fish out the seal. Replace in reverse.

    However, the oil you have recently drained is water contaminated, so inspect the speedo cable boot, and maybe shove some grease under it.

    I find a semi-synth oil can remove some clunk from the gear change too. I would just buy something cheap first though...run the bike to get the gear oil good and hot and change it again. When happy that the milky look is gone, use the semi-synth.
    #10
  11. Sniper X

    Sniper X De Oppresso Liber

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    I have decided to change it again when I get the seal installed and I will address the boot as noted, thanks again all! I am again so happy these things are so easy and cheap to work on.
    #11
  12. Grider Pirate

    Grider Pirate Long timer

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    Just because I happen to have a picture.... here's the filler plug. Yeah, I know you already have it figured out.

    [​IMG]
    #12
  13. Sniper X

    Sniper X De Oppresso Liber

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    Thanks, great picture. I find looking at a parts fische from MAX helps me locate stuff as well!
    #13