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Re-torque Head Bolts?

Discussion in 'Early CJ5 and CJ6 Tech' started by haighfam, Apr 10, 2017.

  1. Apr 10, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    Feb 8, 2009
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    Ran the engine for about an hour yesterday. Brought it up to temp for the first time since tearing it down for restoration. It got all new seals, gaskets and a new head gasket, plasti-gauged the main bearings (it was at factory spec still at 28,000 miles ,checked oil pump etc... Should I re-torque the head bolts?
     
  2. Apr 10, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member 2021 Sponsor 2020 Sponsor

    Tri-Cities WA
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    I remember reading to re-torque around the 500 mile mark.
     
  3. Apr 10, 2017
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Hills of NH
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    It was standard practice in the old days, but I have read that modern gaskests do not require it. I wonder though.

    It would be great if someone here has the "just the facts" on this.
     
  4. Apr 10, 2017
    tarry99

    tarry99 Member

    Northern California
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    The modern gaskets are not the torque issue.........it's the ability of the old bolts and threads having been stretched for many years still having the ability to perform the clamping needed..........run it for a thousand miles and while cold with an accurate torque wrench see if anything has moved....
     
  5. Apr 10, 2017
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member

    Tantallon, Nova...
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    Generally I do the initial torque, then re-torque them after about 5 minutes- they don't seem to change much after that.

    H.
     
  6. Apr 10, 2017
    PeteL

    PeteL If it wasn't for physics, and law enforcement... 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Hills of NH
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  7. Apr 10, 2017
    Daryl

    Daryl Sponsor

    Bonney Lake, WA
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    Oldtime has a great write-up over on the 3b board. I am pretty sure that he is the most knowledgable authority living today on these ancient motors.
     
  8. Apr 10, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Well, since it doesn't hurt to check why not do it?
     
  9. Apr 10, 2017
    Focker

    Focker That's a terrible idea...What time? Staff Member 2021 Sponsor 2020 Sponsor

    Tri-Cities WA
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    X2
     
  10. Apr 10, 2017
    tarry99

    tarry99 Member

    Northern California
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    Torque to factory spec's?..................in the factory engine assembly shop , have you ever seen them heat a motor up to torque it?

    New motors with machined flat surfaces , new studs and / or bolts do not need retorquing.................

    How many folks here when rebuilding a motor have the block or heads resurfaced? or for that matter even check? Use a stretch gauge on the bolts , chase all the threads , use the proper torque lubricant and have their torque wrench checked once in a while?

    Retorque Cold after several complete heat cycles...........

    [​IMG]
     
  11. Apr 10, 2017
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Hand raised. :)
     
  12. Apr 11, 2017
    durangotang

    durangotang Member 2021 Sponsor

    Not Western CO
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    I just idle it up to temp after the install, shut it off, take everything back apart, and retorque the head bolts. Never had any issues with this method.
     
  13. Apr 11, 2017
    1960willyscj5

    1960willyscj5 Well-Known Member

    Mesa, Arizona
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    Do both. Torque 'em now after a day of sitting, and then again at 500 miles, torque 'em again.
     
  14. Apr 11, 2017
    Stout

    Stout Member

    Quakertown, PA
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    I completely rebuilt my engine, including having the head machined and the block tanked. Assembled everything per spec and used Plasti-gauge to ensure everything was A-OK. After a few hundred miles, I started slowly losing antifreeze and I could occasionally smell that sickly sweet smell when I would start the engine. I re-torqued the headbolts and haven't smelled it since (I haven't driven it enough to know if I am still mysteriously losing antifreeze, though.)

    When I re-torqued them using the exact same torque wrench set to the same specs, I noticed some of the bolts turned ever so slightly before the torque wrench clicked.

    So, given that, I say re-torquing the headbolts after a few hundred miles is good practice on these engines.
     
  15. Apr 11, 2017
    jeepstar

    jeepstar Well-Known Member 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Sheboygan
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    I did it because the manual said to. Mine didnt budge since the initial install. Hope that helps.
     
  16. Apr 11, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    Thanks for the input, I will re-torque now and again at the 500 mile mark. Better safe than sorry.
     
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