Primary case leaks

Discussion in 'Dyna Models' started by Dirtrag, Oct 9, 2010.

  1. Dirtrag

    Dirtrag Member

    Hey guys- - -

    I've got a 1999 Dyna Superglide that I've changed the seals and gaskets three (3) times on the primary case and it still is leaking. Could it be that the oil is going thru one of the case bolts? This is driving me nuts to say the least. Anybody have anything similar? :mgun
  2. Beer Hound

    Beer Hound Member

    Can you see where it is leaking, or is it leaving a puddle. Have you checked the drain bolt?
  3. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    As the primary is the lowest point on the bike when on the side stand then any oil leak from any of the 3 oil compartments could be gravitating to the primary and dripping off
    i have previously had an issue with an oil leak from the bolts that mount the inner primary to the gearbox a little hylomar on the bolts near the head and the underside of the bolt head and the locking washer sorted that one

    have also had the gearbox main shaft oil seal drip oil off the primary
    and i believe that on some models the gearbox breather blows oil mist on to the inner primary which condenses into oil and drips from the primary

    give the whole area a good clean with a degreaser and take the bike for a run get it warmed up and check to see if you can identify where the oil is coming from

  4. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    I'm sure you checked and cleaned both mating surfaces and that you made sure there were no cracks in the cover. Did you check to make sure that the gasket area was flat by laying it on a flat surface? The gasket for my '94FLSTC has a raised rubber applied to the gasket that seperates the bolt holes from the oil, don't know about the Dyna gasket. As the post before this suggested check the drain plug and make sure that the area it screws into is not cracked. If your not sure where the leak is, after your next ride wipe the primary cover clean and place a piece of cardboard under it. this should give you an idea of where to start looking.
  5. Jack Klarich

    Jack Klarich Guest

    Arent a few of the bolts longer on these cases maybe in the wrong holes and bottomed out?
  6. Dirtrag

    Dirtrag Member

    This is really driving me nuts! I pulled the thing apart again yesterday. No cracks on the inner case or the outer. It apparently was leaking from one of the lower bolts. The seals are still good. Applied sealant as recommended procedure to the cases. Sealant to the bolts as well as the bolt holes. (The bolts are the same length in the clutch side.) In fact, I got liberal with the sealant! Didn't leak last night until this morning (little spot) and I haven't rode it yet but did move the bike to a clean spot in the garage to check for leakage.

    I'd have rode it today but the wind is blowing something like 45 sideways! Welcome to Amarillo, Texas! Anyway- - - - After using rubber door stops to hold the primary chain, I ordered a regular locking tool from MBSMFG for 20.98. They are the manufacter of the orginal tool. Hmmm- - - -anyway- - This bike must think its a 441 Victor?
  7. blademan

    blademan Active Member

    I have a Softail outer primary that was given to me by a friend of mine. He acquired it because oil was leaking through the casting and was replaced bye the dealer. You may have a bad casting.
  8. Jack Klarich

    Jack Klarich Guest

    Now you may be on to something here:D

    NEWHD74FAN Experienced Member Retired Moderators

    Porous casting though possible is quite rare...if so, primary is fairly low temp so a good cleaning in degreaser followed by contact cleaner (not petrol based) and coating it with fuel tank liner, which is gas/oil resistant should do the trick. I would suspect a bad seal or similar that is hidden from view.
  10. R. Lewis

    R. Lewis Senior Member Retired Moderators

    What are you torquing the bolts down to / Are you tighting them down in a off-set manner / have you checked the case for warpage ? Maybe some old sealant in the bolt hole not letting it to seat correctly?