derby cover leaks

Discussion in 'Transmission' started by billst, Jul 5, 2010.

  1. billst

    billst Member

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    95 flstn. just had the engine rebuilt and the derby cover leaks. took it back and the guy put some kind of sealer around it but it still leaks. i removed the cover and cleaned everything up. noticed there was only an o ring seal. is there not supposed to be a full gasket go on here also? thanks for any info
     
  2. ultrat

    ultrat Senior Member Contributor

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    full gasket better imo....
     
  3. glider

    glider Veteran Member

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    One or the other is OK, the "O" ring is difficult to keep in the grove once it's disturbed but the newer style disc can be substituted in it's place and can be reused a few times.
     
  4. billst

    billst Member

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    thanks guys
     
  5. BUBBIE

    BUBBIE Well-Known Member

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    I have found that i can re-use my derby gasket "O"ring IF I take my time in replacing it and the cover....... Don't tighten ONE bolt but Tighten all a little at a time,,,,, Just enough to HOLD Evenly the derby cover,,,, then TORQUE them USING the Pattern in the book...

    I agree with smitty that you MUST clean off and Dry the fiber gasket and I do also on the rubber "O" ring... I never have a leak....
    (MIND You) ( i DO use oil on the "O" ring on the oil filter)

    I did Have a derby leak once When NOT drying off All residue oil, when replacing the cover.

    Just MY Way!

    signed....BUBBIE
     
  6. Chopper

    Chopper Senior Member

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    I always use a 3 hole full gasket and if it has a o-ring I leave that in as well and never have a problem with leaks, the old three hole covers get overtighten and warp, if you put your cover on a sheet of glass or marble you'll see what I'm talking about, Harley went to a five hole cover not just to sell you two extra bolts but to correct their design flaw they had for years, they also done away with the o-rings and retro the full gasket to the earlier models. A sealer should never have to be used on a durby cover, if your tech does, I would fine a new tech:) Could be your cover is too warped out to seal, might just need a new cover, but I've sealed some bad ones just by using a full gasket with the o-ring.
     
  7. whatyardwork

    whatyardwork Banned

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    I got tired of my 96 leaking out the derby cover after many years.With an unwanted scratch here and there it was enough to make me buy a new 5 hole outer primary cover for the bike.

    That may be overkill, but my derby cover no longer leeks.
     
  8. billst

    billst Member

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    thanks chopper. i ordered a full gasket and will try that in combination with the o ring gasket
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    As Chopper suggested above, put your cover inside down on a sheet of glass (mirror) or a slab of marble and see if it is flat or warped. If warped, you can try GENTLY tapping the high side using a rubber mallet with the cover on a piece of wood (2x4 or 4x4). But don't whack on it sitting on the glass!! Keep checking it between blows until you have it trued. That might be enough to seal it!

    TQ
     
  10. glider

    glider Veteran Member

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    To take it one step further, if it is only slightly warped, use the glass or marble and add some valve grinding compound to the glass and go in a figure eight to flatten the surface. It acts like a lapping plate to straighten the mating surface.