crank bolt right or left hand thread?

Discussion in 'General Motoring' started by swhaley, Jul 8, 2006.

  1. swhaley

    Burt Guest

    I made a post back in Nov 2005 and said that I'd mark the bolt
    (83-lbft on a 2.0L.) Lo and Behold! Today I went to check and
    the bolt hasn't moved. I'm more inclined to believe that the
    tightening is from a cold weld or by other mechanical means.

    The markings I made are from a razor sharp carbon punch.
    I believe the car was driven some 7-8 thousand miles.
     
    Burt, Jul 12, 2006
    #21
  2. swhaley

    jim beam Guest

    interesting. do you have any thoughts on the fact that it has an
    "harmonic balancer" also? they do a lot to reduce rotational inertia
    which might tighten a bolt in one direction, but loosen in another. for
    a balanced crank and flywheel, there's really isn't a lot something low
    mass like this can achieve vibrationally. besides, hondas run
    successfully without them, so i wonder about its actual purpose.
     
    jim beam, Jul 12, 2006
    #22
  3. swhaley

    jim beam Guest

    possible, but that doesn't explain the discrepancy between the galling
    being present on the pre-92 vehicles and there being none on the later ones.
    is the pulley wheel splined? you don't state the vehicle's age.
     
    jim beam, Jul 12, 2006
    #23
  4. swhaley

    Elle Guest

    What model is this?

    I know the 84-87 Civics have an 83 ft-lb pulley bolt spec,
    but some have a 2.9L engine?

    Little discrepancy that we should clear up to make sure
    we're on the same page.
    Did you also try to break the bolt free? If so, any estimate
    of how much torque was needed?

    Thank you for doing this.
     
    Elle, Jul 12, 2006
    #24
  5. The purpose is to transfer US $100+ from my pocket to Volvo's coffers
    occasionally (the first lasted about 150K miles). For those trying to
    picture this device, imagine your crank pulley with a strip of rubber
    running the circumference and bonding the pulley part to the core. The
    rubber eventually shears....

    For whatever reason, the B230 engine has a harmonic balancer - also called a
    harmonic damper... not sure which term is official - while the very similar
    B23 engine has a conventional pulley. Hmm.

    Mike
     
    Michael Pardee, Jul 13, 2006
    #25
  6. swhaley

    jim beam Guest

    it does indeed!
    which is even more interesting. it definitely will damp the rotational
    inertia spikes that will transient between the crank and those rotating
    masses the pulley drives.
     
    jim beam, Jul 13, 2006
    #26
  7. swhaley

    Burt Guest

    The galling was probably caused by the lack of a vibration damper.
    At best guess, the 92 Accord's balancer shaft may have helped. This
    and the high bolt torque, 160-lbft, may explain why the galling isn't
    present on the post-92 Accords, which I've also witnessed myself.
    88 Accord...no spline.
     
    Burt, Jul 13, 2006
    #27
  8. swhaley

    Burt Guest

    Successful? What about the galling on the crank bolt head you've
    talked about. That could've been caused by the torque pulsation of the
    vibrating engine.

    Take for instance, when ever I do a brake lathe without the vibration
    damper on the brake disc there is a wave effect on the surface. On
    the crankshaft, these wave (oscillating) effects can transfer eat up the
    transmission gears or various parts.
     
    Burt, Jul 13, 2006
    #28
  9. swhaley

    Burt Guest

    88 Accord, around 286k miles.
    Yes, I could break it loose but I'd just broke loose the 92 Accord
    engine block coolant drain bolt today which took about 150-lbft
    and pretty exhausted.

    Tell you what, tommorow I will:

    1. Hook up a beam torque wrench to a chain hoist horizontally
    and slowly chart the effects during unbolting.
    2. Do the same to my other 92 Accord.
    3. Both cars will be torque and loosen and chart the difference.
    4. Both cars will be marked before loosening.

    There is a problem with #1. My beam torque wrench only goes
    to 150 ft-lb, which is design for head work only. I have a clicker
    type rated at 200-lbft, but this is inconvenient. Other than this,
    what would be another practical way to measure the loosening torque?
    Your welcome.
     
    Burt, Jul 13, 2006
    #29
  10. swhaley

    Elle Guest

    :)

    That's the other one that's a bear for the home mechanic, as
    you may have heard.

    I will say that my coolant block bolt was only tough the
    very first time I freed it.
    I appreciate your enthusiasm, but I don't think doing a
    careful check of the "break free" torque will reveal
    anything new. We all already know that after several years
    and many miles of driving, the bolt becomes very tight.

    If your Accord's pulley bolt is not very tight, then this
    just suggests (to me) little time has transpired since it
    was last freed.

    There are some other suppositions that one can make, but I
    don't care to venture into what may be fantasy land.

    It certainly could be simply "cold welding" of this fine
    threaded bolt subjected to terrific dynamic loads and
    temperature variations.
     
    Elle, Jul 13, 2006
    #30
  11. swhaley

    Burt Guest

    As you've probably known, the bolt has a very shallow head.
    This was the main problem. I had to build a jig to steady the
    tool. After some thought the jig was nothing but two blocks
    of wood (a 2x4 and a 2x1) and it was freed easily. :~)
    I see. But looks like I do this at a later time. I'd set up the
    chain come-along but I can't locate a buddy of mine who
    has a 5-ton crane scale.

    The 88 Accord pulley bolt which I believe had driven some
    80k miles before the belt was changed was loosen easily. The
    92 Accord was driven about the same miles but the bolt
    needed help from a machine.
     
    Burt, Jul 14, 2006
    #31
  12. After 375k I've done a bunch. It was a bitch the first time and it was a
    bitch the most recent time. In all cases the usual 250ish foot-pound
    impact wrench on a quarter-inch hose wouldn't budge it, though I wasn't
    willing to spend all day on it before breaking out the big guns.
     
    andrew m. boardman, Jul 20, 2006
    #32
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