1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Rear main seal removal and replacement

Discussion in 'Early CJ5 and CJ6 Tech' started by sparky, Sep 11, 2008.

Page 3 of 4
  1. Sep 14, 2008
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Re: Rear main seal removal

    Hmm. I'd certainly Plastigage the bearings. Engines, like people, don't have to be perfect to function normally. If the clearance isn't compromised, and the groove is narrow compared to the width of the bearing, function will not be compromised.

    Not sure how well you can Plastigage the mains in place - maybe Mike or Nick or someone who's done it will weigh in. It may work ok if the other caps are in place.
     
    timgr, Sep 14, 2008
    #41
  2. Sep 14, 2008
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
    Joined:
    Sep 22, 2002
    Messages:
    5,349
    Re: Rear main seal removal

    Using Plasti-gage on the engine with it hanging in the Jeep would be just about impossible right now. You would need the plasti-gage in the upper bearing shell, no way to get it there or get it out without affecting the reading. If the journal is good I would just buy new bearings and slap them in. Otherwise your choices are pretty much limited to what you said before Sparky, take it somewhere and let someone else do it.

    Sorry to hear about the problem Sparky!!!
     
    Mcruff, Sep 14, 2008
    #42
  3. Sep 14, 2008
    Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    San Diego,...
    Joined:
    Mar 30, 2007
    Messages:
    3,383
    Re: Rear main seal removal

    Tim, could you please esplain this concept to my wife :D (j/k)

    Sparky.....just 2 words......ROAD TRIP!!!!!!.....just let me know if you want me to send you the green boots to keep you company. R)
     
    Don X, Sep 14, 2008
    #43
  4. Sep 14, 2008
    termin8ed

    termin8ed I didn't do it Staff Member

    Mason, MI
    Joined:
    Dec 22, 2002
    Messages:
    4,422
    Re: Rear main seal removal

    sounds familiar... 2 years, 2 months, 10 days later.

    eh, I'll just replace the camshaft...

    Eh, guess I might as well fix the bent valve too...

    Eh, what the hey.

    Hopefully its just contained to the one bearing. If its just the bearings and the crank's good, swap them out and run it for another year untill your more settled in.
     
    termin8ed, Sep 14, 2008
    #44
  5. Sep 15, 2008
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,525
    Re: Rear main seal removal

    I'd slap her back together and run it.
    then you do the rebuild at your convience.
    it was running okay before, don't worry about it.
     
    jpflat2a, Sep 15, 2008
    #45
  6. Sep 15, 2008
    neptco19

    neptco19 That guy....

    Athens, GA
    Joined:
    Sep 26, 2003
    Messages:
    1,381
    Re: Rear main seal removal

    Oil pressure good before? Put it back together and enjoy :D
     
    neptco19, Sep 15, 2008
    #46
  7. Sep 15, 2008
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
    Joined:
    Sep 20, 2002
    Messages:
    9,221
    Re: Rear main seal removal

    Says the man who told me to look at the bearing inserts in the first place. R)

    Oh, and yes it was. I've put plenty of effort into that oil pump. :D
     
    sparky, Sep 15, 2008
    #47
  8. Sep 15, 2008
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,525
    Re: Rear main seal removal

    :)
     
    jpflat2a, Sep 15, 2008
    #48
  9. Sep 16, 2008
    neptco19

    neptco19 That guy....

    Athens, GA
    Joined:
    Sep 26, 2003
    Messages:
    1,381
    Re: Rear main seal removal



    :oops:
     
    neptco19, Sep 16, 2008
    #49
  10. Sep 16, 2008
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Re: Rear main seal removal

    Don't worry. Be happy! R)
     
    timgr, Sep 16, 2008
    #50
  11. Sep 26, 2008
    w3srl

    w3srl All-around swell dude Staff Member

    Port Orange, FL
    Joined:
    Nov 6, 2002
    Messages:
    4,275
    Re: Rear main seal removal

    Ok, so I'm a bit confused on the plastigage thing. When the main caps torqued into place you should have more or less even pressure/clearance all around the bearing/crankshaft interface, no? If not, then something is out of round and you would know about it pretty darned quickly.

    BTW, I'm with the others here about putting it back together. It ran ok before, didn't it? I've torn a lot of engines down over the years and I've yet to come across one that had absolutely perfect main bearings in it...
     
    Last edited: Sep 26, 2008
    w3srl, Sep 26, 2008
    #51
  12. Sep 26, 2008
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
    Joined:
    Sep 20, 2002
    Messages:
    9,221
    Re: Rear main seal removal

    Doesn't matter.

    It's gonna go back together the way it is if I can get the rear main out tomorrow.

    No time to fuss with it otherwise. It'll have to do for now. :)
     
    sparky, Sep 26, 2008
    #52
  13. Sep 27, 2008
    Mcruff

    Mcruff Earlycj5 Machinist

    Albertville, AL
    Joined:
    Sep 22, 2002
    Messages:
    5,349
    Re: Rear main seal removal

    Not quite Steve, lets just use a few imaginary numbers here to illustrate my point. The main journal on the crank is 2.250", the bearing is designed to run a .0013 - .0017 " clearance meaning the bearing bore in theory is 2.2513-2.2517. When you put the engine together to start with and use plastigage the engine is upside down making all the clearance in the lower bearing shell cause you are doing this dry and there is no oil to take up space, the plastigage registers the space. When you have the engine installed the crank pulls itself down from gravity making the open clearance on the top of the journal., in the exact place you wanted to check clearance and can't. When the engine is running, this clearance is taken up with oil.
     
    Mcruff, Sep 27, 2008
    #53
  14. Sep 27, 2008
    kaiser_willys

    kaiser_willys Well-Known Member

    Joined:
    Jan 7, 2007
    Messages:
    1,524
    Re: Rear main seal removal

    ok first off dropping the tranny isint gonna help at all, 2 piece seal, no access form the rear of the motor, secondaly if it were me i would try to find a plastic or teflon would be better dowel, thet is sturdy but flexable, and drive the seal around enough to grab it with vise grips and finish by pulling it out, hope this helps you out:beer:
     
    kaiser_willys, Sep 27, 2008
    #54
  15. Oct 1, 2008
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
    Joined:
    Sep 20, 2002
    Messages:
    9,221
    Re: Rear main seal removal

    It's out!

    1/4" oak dowel and the corkscrew on the other side. Just kept working on it. Only took me about five minutes to finish up, this after I thought it was going to take quite a bit longer. :rofl: Ah well, it's out, that's what matters!

    Thanks for the help guys.

    Gonna just put it back together and overhaul later. Winter's coming and the Jeep isn't driven that much anyway.
     
    sparky, Oct 1, 2008
    #55
  16. Oct 1, 2008
    kaiser krawler

    kaiser krawler kaiser krawler

    naples florida
    Joined:
    Apr 19, 2007
    Messages:
    113
    Re: Rear main seal removal

    good deal sparky. i hope you have better luck putting it back together. after i did mine i still have a bit of a leak, i either did'nt get the caps sealed or my crank journal is worn from the old rope seal. i got rid of 95 percent of my leak, but still get a small drop of oil when i park it.
     
    kaiser krawler, Oct 1, 2008
    #56
  17. Oct 1, 2008
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
    Joined:
    Sep 20, 2002
    Messages:
    9,221
    Re: Rear main seal removal

    Eh, it can't be any worse than what I had before. Anything is an improvement (hopefully).
     
    sparky, Oct 1, 2008
    #57
  18. Oct 1, 2008
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
    Joined:
    Jul 30, 2003
    Messages:
    8,525
    Re: Rear main seal removal

    good call
     
    jpflat2a, Oct 1, 2008
    #58
  19. Oct 1, 2008
    Homebrew2

    Homebrew2 Member

    Dunlap, CA
    Joined:
    Aug 17, 2007
    Messages:
    511
    Re: Rear main seal removal

    Yeh, wondered if the new one was successfully in yet ...
     
    Homebrew2, Oct 1, 2008
    #59
  20. Oct 1, 2008
    Vanguard

    Vanguard Take Off! Staff Member

    Vista, CA USA
    Joined:
    Aug 30, 2006
    Messages:
    2,259
    Re: Rear main seal removal

    Keep thinking like that and you'll have to change your username to Vanguard. R)
     
    Vanguard, Oct 1, 2008
    #60
Page 3 of 4
New Posts