Crank pulley bolt (Timing belt replacement DIY)

Discussion in 'General Motoring' started by sonata owner, Apr 7, 2006.

  1. sonata owner

    sonata owner Guest

    Hi all,

    I'm having a hard time tigthening the crank pulley bolt with the proper
    torque (about 130 pounds).
    A click-type torque wrench wouldn't work, since the crank turning while
    applying torque.

    Under-torque may ruin crank sporacket and others. I heard horror
    stories about under-torque.
    There are not many terrible stories about over-torque. I can imagine
    that it may ruin the crank pulley bolt.

    I have an electric impact wrench, which says it produces maximum 185
    pounds torque. A cheap one at Wal-mart, but it works fine.

    I ran the impact wrench on the bolt until I heard "Clang" sounds coming
    from the engine case. Which could be a sign that tells "hey it is

    What kind of risk I'm running here? Any ideas?

    Should I buy an impact wrench extension socket or something?

    sonata owner, Apr 7, 2006
  2. sonata owner

    sonata owner Guest

    Oops, it is Sonata 99 V6. The crank pulley has only one big bolt.
    sonata owner, Apr 7, 2006
  3. sonata owner

    hyundaitech Guest

    That's not a terribly powerful impact, so you're probably fine as far as
    tightening the bolt with it. I suspect you'd have a hard time finding a
    professional who doesn't tighten these bolts with an impact. The
    difference is that you probably don't have the experience to be able to
    use reasonable judgment with an impact on a crank pulley bolt.

    A clanking from the engine case disturbs me, however. I'd expect the
    whack-whack from the impact wrench, but no noise from the engine case
    itself. Make sure you've got everything installed properly and that the
    engine turns all the way around (two crank turns) by hand.
    hyundaitech, Apr 7, 2006
  4. sonata owner

    sonata owner Guest

    Thank you much. That helps.
    sonata owner, Apr 7, 2006
  5. sonata owner

    Lakeport88 Guest

    Related topic: I managed to break the crank pulley bolt free without
    using an impact wrench for a DIY timing belt change. Here's how I did
    it for any other brave DIY's:

    - Jack the car up with a stand on the passenger side
    - pull the fuel pump fuse
    - start the car and run it until the fuel pressure drops enough so that
    it stalls (it will stall after 5-10s)
    - use a 1/2" drive johnson bar with crank bolt socket and enough
    extensions to clear the wheel well (you'll need about 18" long of 1/2"
    drive extensions to clear the wheel well). Use a jackstand to support
    the free end of the extensions+ johnson bar
    - put a long pipe on the end of the johnson bar so that the pipe
    touches the ground in front of the car. The pipe will react the
    starter motor torque. Note the crank pulley rotates clockwise when
    viewed from the end (from passenger side of vehicle).
    - get an assistant to crank the starter (briefly). The starter easily
    has enough torque to break the crank bolt loose.

    I imagine there might be a risk of breaking a tooth off the ring gear
    or the starter motor pinon, but it worked for me!
    Lakeport88, May 1, 2006
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