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Rear Main Oil Leak

Discussion in '80-Series Tech' started by Curran, Feb 1, 2004.

  1. Curran

    Curran

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    First off, yes I did do a search and I read through the FSM with out gaining answering my question.

    My truck is leaking oil pretty heavily. :'( It appears to be coming from the little semi-circular hole on the face where the engine and transmission mate together (right above the front sway bar).

    The local hot rod guy climbed under and took a quick look. He said the it was my rear main seal. My question is how do you properly diagnose this? And what’s a good guess how much is this going to cost me to have fixed?

    Thanks.
     
  2. cruiserdan

    cruiserdan SupportingVendor Emeritus Moderator

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  3. Darwood

    Darwood

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    >>It appears to be coming from the little semi-circular hole on the face where the engine and transmission mate together (right above the front sway bar).<<

    That's exactly where mine is leaking. However I'm fortunate enough that it's just barely dripping from there. Let me know if it is the rear seal. I don't see how it can be the oil pan, but I'm not entirely sure what's going on above the little semi circle.

    I did remove the plastic inspection plug and found that what I could see was remarkably clean considering this is where the oil is dripping from. I think I need a mirror to inspect further.

    I've read through the other post and I couldn't make the info apply to this situation.
     
  4. landtoy80

    landtoy80

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    When my rear main retainer was leaking it was a good drip but not flowing.
    If it is blowing out oil then is would be the rear main.
    It is a gamble to deside what to fix. If you have a tranny jack (not the one that goes in a floor jack), drop the tranny. That way you be sure to fix it.
    My bet is the oil pan is leaking.
     
  5. Rookie2

    Rookie2

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    I'm dealing with this issue right now too. It's difficult for me to be sure whether it's the seal between the retainer and the upper oil pan or if it's the rear main seal. If you pull the cover on the port hole to the tranmission, you should be able to hold a small mirror up in the hole to look at the back side of this retainer/main seal area. My leak is slow right now with oil coming from the bottom of the side of the retainer, but there is some oil also above the bottom of the retainer, below the main seal, so it's hard to tell. I've decided to drop the oil pans and reseal, because it seems to be much easier than pulling the tranny. Hopefully Murphy will cut me a break.

    If you're going to have someone elst do it, you might check the difference in cost to make your decision. Seems to be the prodominant opinion on this board, that rear main seal leaks are rare/er.

    Good luck,
    Rookie2
     
  6. raiderob

    raiderob

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    u better hope that it isn't the rear main seal leaking cuz that is going to cost you some money-they have to pull the tranny out to get to that seal thats costly