Fluid leak from hole in mainshaft

Discussion in 'Transmission' started by fpd4308, Jul 7, 2010.

  1. fpd4308

    fpd4308 Member

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    It seems like some tranny fluid is leaking from the hole on the clutch side of the mainshaft, around the clutch release pushrod and into my primary. It leaks more on long trips but still seems fairly minor, sometimes none, sometimes about silver dollar sized puddle. Any suggestions on where the leak may be coming from. By the way the motor is a 1996 80" Evo on a softail.

    Thanks
     
  2. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Is the leak coming from between the inner primary and the trans pulley? If so the main seal behind the drive pulley is leaking. Usually some dirt of debris has gotten between the seal and the mainshaft.
     
  3. fpd4308

    fpd4308 Member

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    That is what I thought it probably was so I pulled it apart and the oil is actually coming from the hole in the center of the mainshaft, where the clutch adjustment bolt goes in
     
  4. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    If it's leaking inside the primary, where is this puddle your talking about. Are you running an open belt primary?
     
  5. fpd4308

    fpd4308 Member

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    Yup belt primary. The puddle is right below the drain plug in the primary, which I just keep out for just this type of thing.
     
  6. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    When you serviced your trans. how much trans fluid did you put in? The main shaft is hollow and the end that is through the bearrings on the trap door should be above the fluid level. While some fluid may splash up from the bearings there should a minimal amount traveling through the shaft. This serves as lub for the pushrod. Check your fluid level in the trans.
     
  7. glider

    glider Veteran Member

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    Also check the vent tube on the trans, it may be blocked and heat expansion is pushing the trans fluid through the clutch push rod.
     
  8. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Thanks Glider, that makes sense that the pressure inside the trans would push the fluid to the path of least resistance.
     
  9. fpd4308

    fpd4308 Member

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    Thanks for the help I will do both those things.