Big Oil Leak behind Harmonic Damper

Engine, Trans & Driveline

  1. avidflyr

    avidflyr Well-Known Member

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    My 400 BB was recently Rebuilt (500 miles). Oil pours out (behind Damper) after Engine is shut down. It can idle for 30 min. with no leak. I have heard of some problems with faulty timing chain covers manufactured with crank seal off centered.
    It didn't leak until recently 400+ miles. Oil pan and windage tray are new. I have retourked the pan bolts to make sure all is tight.
     
  2. 91r/t

    91r/t FBBO Gold Member FBBO Gold Member

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    On the small blocks they say to install the dampener before tightening the cover/waterpump bolts to center the seal on the dampener. The big blocks have those 2 pins that don't allow the cover to move much so I am not sure that trick does much good. Wierd that is happens only when sitting and not running.I'd say maybe the seal tore or distorted but you'd think it would leak like a siv running. Unless while running the oil doesn't pool by the seal and once idle and sitting it settles and starts to leak? Odd case either way.
     
  3. Daves69

    Daves69 Well-Known Member

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    One could open up the cover pin holes I would think. Sounds like it's coming off in the near future anyway.
     
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    • Fran Blacker

      Fran Blacker FBBO Gold Member FBBO Gold Member

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      New harmonic damper or used? If used could be a groove at sealing sealing surface. A "Speedy Sleeve" would fix that. Pull the damper check that first.
      Timing cover if it's a new one maybe but?
      Edit: Check the key way on damper in corners for cracks.
       
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      • miller

        miller Well-Known Member

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        And, make sure the seal is installed the right way.:eek:
         
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        • dadsbee

          dadsbee FBBO Gold Member FBBO Gold Member

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          Was the slinger installed?
           
        • dryheat

          dryheat FBBO Gold Member FBBO Gold Member

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          How much pours out? Is it a few drops or more than that?
           
        • avidflyr

          avidflyr Well-Known Member

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          Thanks for all the input ! When the damper is out, I'll measure the distance from the crank snout to front cover seal opening at 4+ locations, before I remove the front cover. This will tell me if the front cover is off center to the crank snout... Having trouble removing the pulley off the damper. Seems the bolts (6) were installed with red locktite.
          Trying not to round off the bolt heads. It is a wide pulley and the arms on the puller are not long enough to reach the
          back of the damper. Tool rental shops don't have one either. may have to cut off the pulley...UGHHA!!
           
        • Dipstick

          Dipstick Well-Known Member

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          If you're planning on using a claw puller to remove the damper, don't...you'll destroy the damper. Use a 6-point socket on the pulley bolts to avoid rounding them off.
           
        • miller

          miller Well-Known Member

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          After the crank pulley is off, look at the dampner, at the inner part of it. Should be two threaded bolt holes...that are used with a two-bolt type puller. That's how the dampner is pulled off the crank.
          If you try to use a claw type puller, on the outer ring, it will mess up the dampner. Outer ring is pressed into place, with a rubber slip, that holds it in place.
           
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