Fixing Primary Inner Case Leak

Discussion in 'Motorbike Technical Discussion' started by Manjo, Apr 28, 2008.

  1. Manjo

    Manjo Guest

    Inner Primary Case appears to be leaking at bolt to tranny. Will
    applying silicone to the bolt and torquing the bolt to spec stop the
    primary oil leak?

    Long version: I’ve checked the archives and didn’t find any post on
    this problem (but that doesn’t mean there’s none there). My 2002 FXDL
    Low Rider has a leak behind the inner primary case. It’s not
    crankcase engine oil: the leaking fluid is clear, clean, and with
    almost no odor (whereas on the oil dip stick, the crankcase engine oil
    is not clear and is dark).

    I raised the bike on a 2-arm m/c jack and sprayed brake cleaner around
    the area to the rear of the primary case and to the inside between the
    case and the oil pan where I saw the leak. I cranked (but not started)
    the engine several times to get the oil to leak (turns out it will
    leak by itself now without the engine running). Oil drops are
    accumulating on a protruding post at the back of the inner primary
    case where the case bolts to a threaded transmission tab. I can see
    the flush end of a threaded bolt that appears to come from inside the
    inner primary case through the case post that threads into the
    transmission tab. The end of the bolt points toward the oil pan on
    the other side of the transmission tab. The oil pan is clean.
    There’s no oil on the upper portion of the transmission tab that
    implies the oil is not coming from anywhere above the bolt (like from
    the tranny).

    The FXDL factory manual shows the inside of the inner primary case
    (but not the back of the case that faces the tranny). The inner case
    drawings show three (3) Primary-to-Transmission locktab bolts located
    on the right-half of the case (behind the clutch). One of the bolts
    looks to be in the right spot (the lower-right bolt) where I see the
    leak. So I'm assuming the bolt is loose, and/or any sealer applied
    between the inner case and the transmission has broken down.

    If I have isolated the leak correctly, I think there are a couple
    options, but I don't know which is best (or correct):

    Per the manual all my options would require removing the primary
    chaincase cover then removing the primary chain, clutch, and
    compensating sprocket to gain access to all three P-to-T bolts, then …

    A. Torque down all three bolts to spec and see if that stops the

    B. Apply silicone sealer to all three bolts then torque them down and
    see if the leak stops. This was done in an archived post to fix a
    different primary leak.

    C. Completely remove inner primary case, clean off the contact points
    for all three P-to-T mounting bolts AND P-to-Engine bolts, add
    silicone at the mounting points, then bolt the case back up to the
    engine and transmission.

    Are there other options??

    The C. option sounds like a lot of work, but it would give me access
    to the Jackshaft oil seal for a visual check. There's also mention of
    a "crankcase lip O-ring" that's discarded and replaced when removing
    the entire inner primary case.

    Am I on the right track here? If so, any thoughts on which is the
    best option (or is there a better option)??

    TIA for any tips, suggestions, comments.

    Manjo 2002 FXDL
    Manjo, Apr 28, 2008
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  2. Manjo

    Manjo Guest

    Sorry. Accidentally posted here, but if anyone has been unlucky
    enough to have this same problem and knows the fix, please post.

    Otherwise, best regards, Manjo
    Manjo, Apr 29, 2008
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