Register now to get rid of these ads!

Hot Rods 392 Hemi Rear Main Leak

Discussion in 'The Hokey Ass Message Board' started by moparjack44, Nov 26, 2016.

  1. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    I have replaced (twice) rear main seal. Can not get it to stop leaking? I have heard that the shim provided is not thick enough. Has anyone else heard of this? If yes, what is the solution? What should the thickness be?
    Jack
     
  2. tom feland
    Joined: May 7, 2009
    Posts: 26

    tom feland
    Member
    from Norman, OK

    I had a similar problem recently on my 392. It turned out that there are two very small pieces of rubber that go into
    the grooves under each side of the main cap. Once the main cap is torqued the ends of these rubber pieces are trimmed off with a razor blade. My original main seal kit either didn't have these or somehow I didn't notice them.
    It will definitely leak without them. Once I installed a new rear main seal and installed these two pieces.....no leak.
     
  3. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Thanks Tom. I went thru that also. On my 2nd one, I made sure I used the supplied shim(s), but best I remember, only had 1 shim? Your seal had 2 shims? I got my seal from Hot Heads, do you recall where you got yours, and how long ago? I have another seal (Hot Heads), but haven't installed it yet, waiting for answers. I have been told the 1 shim isn't thick enough. When installing the other one, I thought it looked as though the seal was lower (just a little) than top of the cap journal.
    They don't make a seal any more specific for the 392, that's why the shim(s) are included, so I have been told?
    Jack
     
  4. Kona Cruisers
    Joined: Feb 4, 2007
    Posts: 1,074

    Kona Cruisers
    Member


  5. There's two shims, one for the block side and one for the cap. Just did this 2 weeks ago.
     
  6. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Not that I am aware of. The seal was/can be replaced by simply removing the cap, and slipping in the seal, and torquing back the 2 bolts holding the cap.
     
  7. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Any leaks, or is the engine out of the car?
     
  8. tom feland
    Joined: May 7, 2009
    Posts: 26

    tom feland
    Member
    from Norman, OK

    Jack, I got my last rear main seal set from Hot Heads, about 3 months ago.
    There were six total pieces: two piece seal, two fiber shims, and two very
    Small rubber pieces. The rubber pieces go in the grooves under the sides of
    The main cap and squash out to each side of the main as torque is applied.
    They need to be trimmed with a razor blade so that the rear pan seal fits
    Properly. The instructions don't mention the rubber pieces, so I
    Somehow overlooked them the first go around.
     
  9. saltflats
    Joined: Aug 14, 2007
    Posts: 10,313

    saltflats
    Member
    from Missouri

    Maybe a picture would help for some of us to maybe be some help.
     
  10. The 392 I did is out of the car for now.
     
  11. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    ????? I remember those 2 small rubber parts, but I swear I do not remember using them. That just might be my problem. I wonder why they were ignored from the directions. I will check that out.
    Thanks Tom.

    Jack
     
  12. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    STILL trying to resolve this leaky rear mail seal on 392 Hemi. Researching options, I found a Fel Pro gasket that is for the 354 Hemi, but not for 392. What is difference in the 2 that would have effect on rear main seal? I know of most internal differences, heads, bore, etc, but rear main seal?
     
  13. Never2old
    Joined: Oct 14, 2010
    Posts: 648

    Never2old
    Member
    from so cal

    I've got this problem with my 331.
    My "parts store" set didn't come with any shims but the block side has two wings that fit in slots in the block.
    Has anyone measured the supplied shims thickness?
    I'd sure like to know so I have a place to start.
     
  14. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    I do not have the proper tool to measure anything that thin, sorry I can't be of any help. Contact Hot Hemi Heads, they can get you the correct seal. The seal is made by Best Gaskets.
     
  15. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    I am Soooooooo embarassed. Just by chance I "properly" diagnosed my leaking problem. It was not the rear main seal. It was a crack in the oil line going from sending unit to the gauge. The crack was well hidden in the line where it was routed near rear of engine and tranny. Embarassing, but very happy to stop the leak.
     
  16. TA-DA fixed !!!
     
  17. BJR
    Joined: Mar 11, 2005
    Posts: 6,517

    BJR
    Member

    Thanks for sharing your mistake with us. A lesser man would have made up something, or never replied with a fix. We all screw up, takes balls to admit it.
     
    73RR and hipster like this.
  18. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Check with Bob or Eric at Hot Heads, but I don't think the 331 requires shims, only the 392?
     
  19. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Thanks.
     
  20. Never2old
    Joined: Oct 14, 2010
    Posts: 648

    Never2old
    Member
    from so cal

    My 331 is a '55 so it takes the same seal.
     
  21. I just blew up two $30 electronic ceiling controllers because of a shorted light wire on the light fixture. I'm slow but make up for it by not being very fast. That short was hard to find.
     
  22. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Are you sure? I know the 354 does not require the shims. It is my understaning only the 392, because it has different size crank than the 331 and 354?
     
  23. Never2old
    Joined: Oct 14, 2010
    Posts: 648

    Never2old
    Member
    from so cal

    My mistake on the crank seal interchange.
    Regardless, I'm having a problem with the rear main seal leaking while on the engine stand and priming.
    Rotating the crank had no effect.
    I'd sure like to know where to start with a shim thickness.
     
  24. moparjack44
    Joined: Nov 8, 2005
    Posts: 467

    moparjack44
    Member

    Sorry I can't help, but cost for 392 RMS reasonable. You could get the 392 RMS, either from Hot Hemi Heads, or Best Gaskets direct. Call HHM, Bob or Eric good folk and will be gald to help. They probably know thickness of the shims. They are in LoGap, NC, Phone (336)352-4866.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.