No announcement yet.

rear main seal

  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Either way you choose to install the seal a dab of sealer on the end of the seal is a good bet. I have done them the offset way for years with good results. In my case a leaky rear main has always been something else leaking(Knock on Wood). Luck Doofus, yes that's my screen name.


    • #17
      Yes, proper installation is the first requirement.

      No, it's not a guarantee there will be no leaks if the engine has combustion blow-by and thus pressure in the crankcase pushing the oil out past the seal.

      Maybe, every rebuild should have best-science cylinder wall finish; i.e. a precision honing with diamond stones. The rings seating and sealing against round and straight cylinder walls keeps combustion pressure out of the crankcase.

      jack vines


      • #18
        You can still get excess crankcase pressure if your breather cap is plugged. I had a 6 that leaked every where. I replaced several gaskets and the leaking was just as bad, I couldn't stop it. I was just checking things one day and lifted the breather cap off and the engine pitch changed and the telltale smoke from the vent tube stopped. When I replaced the cap the engine was chugging a little bit different and the smoke from the vent pipe reappeared. At the time I wasn't sure of the cause until I looked at the breather cap and it was plugged solid. After cleaning the breather cap it was like a new engine smooth and responsive (for a small 6 that is). So often we go down the wrong road chasing shadows, I have done it many times, even experienced service people suffer from the same thing from time to time. It is not usually a great loss to them because the customer pays. I took my car back to a service shop 4 times for an aledged O2 sensor when all the time it was the fuel pressure regulator. They got head strong on that issue and would not budge until I got heavy with them and forced then to look a little deeper in to the problem, they were then so proud that they found the problem. This wasn't a Mom and Pop shop it was a large dealership.


        • #19
          I've given up; my last 2 V8 rebuilds developed the dreaded rear engine oil leak, not much, but still, drips suck. I suspect the fact that I trimmed that stupid arch gasket, not much but there was no way it fit, even with the engine upside down on a stand! Anyway, I now use a "diaper": 2 wadded up paper shop towels jammed between the oil pan and bell housing, which I change out every so often. I know it's hokey, but it prevents drips (not leaks) and the 259 sure purrs so I don't sweat it!