Engine Oil leak

Discussion in 'Engine, Fuel and Exhaust' started by Traceman, Aug 5, 2013.

  1. Traceman

    Traceman Member

    So coming home from Georgia yesterday we developed an oil leak on the left side of the motor. It is not visible anywhere above or around the jugs. The motor, trans, and primary are all untouched. It appears to be coming from behind the primary about even with the primary drain plug. At first I though it was primary fluid but turns out that I was about a qt and a half low on engine oil. Any ideas where this leak is coming from? Its a 96" twin cam. It is not transmission fluid. This was dirty black fluid. I pulled the derby cover off and the oil was at the level it should be.

    BUBBIE Well-Known Member

    A QUICK Guess:

    Engine Halves leaking at some point. OR oil filter leaking OR oil cooler and all running Back.

    That much engine oil Low should be a big Clue...:dknow.

  3. dbmg

    dbmg Guest

    2nd oil filter or cooler sprung a leak ???????????
  4. Redfish-Joe

    Redfish-Joe Senior Member

    I had a leak on one of the plugs in the front of the oil filter once. Pulled it, cleaned and re-tefloned and no problem since.
  5. seadogbrr

    seadogbrr Member

    Agree with the oil cooler/filter leaking. I had the same thing happen it was a oil line fromt he cooler leaking.
  6. Traceman

    Traceman Member

    Looks like there is another piece to the puzzle. I am low on trans fluid also. It is suggested that it is the mainshaft seal. With me having air ride on my bike I may have had the belt tension too tight which stressed the shaft. How big of a job is this?
  7. JTs Dad

    JTs Dad Member

    The most common leak is the two lower transmission side plate (bearing housing) screws. It's not the chrome cover that says "six-speed" on it, it's the plate that the cover bolts down too. There is an exhaust bracket attached at this point and these two screws always seem to loosen up. Check those two screws - I'll bet they're loose. Just tighten them and the leak will disappear. Had this happen to me a month ago, when it's on the jiffy stand it drips down right at the plug just like your describing...
  8. brownfoxx1

    brownfoxx1 Active Member

    switch to red line shockproof gear lube, its thick & pink in color.
  9. Redfish-Joe

    Redfish-Joe Senior Member

    If push come to shove, use a tracer dye available at Autozone. They come in two colors, orange and green. Put one color in the oil and the other color in the tranny. Ride it a bit and check with a black light. At least you will know which area to start digging into. Oh if you get no hit with the black light then the primary is the culprit.
  10. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    The main shaft oil seal is perhaps not to difficult to do provided you have the correct tools and a wee bit of experience using them
    The primary needs to come off all of it then pull the bearing inner race from the main shaft as the seal is behind it
    If you then drill some small holes in the metal part of the seal and screw in some self tapping screws you can pull on them to pull the seal out then just slip it off the end of the main shaft
    Use some rigid plastic pipe of a suitable size to drive the new seal into place
    When fitting the bearing inner race ensure you do leave sufficient space between it and the seal so that you can get a puller in if needed in the future
    Ensure you seal the bolts between the inner primary and the gearbox it might be worth replacing all the seals and inner primary bearing while in that far
    Best tool to have is the service manual read it and be well acquainted with what you are going to do prior to starting
    You will also need special tool to remove and fit the bearing inner race on the main shaft low cost versions can be found on ebay