need help finding engine tork spec?

penna135penna135 Member Posts: 1
edited March 2018 in Chevrolet
for fly wheel on 2008 chevy colorado lt 3.7 5 cyl and should these bolts be lock tight?


  • 0patience0patience Member Posts: 1,712
    The info I have says 60 Ft-lbs, but check with your local auto parts store and they should be able to look it up for you.
    As for locktite, I use Locktite Blue 242. Do not use red Locktite.
    The only thing worse than having a flexplate bolt come loose, is trying to get bolts loose that someone has used red threadlocker on.
  • thecardoc3thecardoc3 Member Posts: 5,614
    I had time to look up the specification. The flywheel bolts are TTY (torque to yield) and must be replaced every time they are removed. The torque spec is 30lb/ft plus an additional 45 degrees.

    The specification is the same for both automatic and manual transmission flywheels.
  • crossroads14crossroads14 Member Posts: 2
    This should be stated in manual. However this thing is tricky a bit, but according to my experience, 40 lb/ft and above should be fine with 45 degrees. Unless I'm the one I'm doing, I could make adjustments, but that's fine.
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  • thecardoc3thecardoc3 Member Posts: 5,614

    However this thing is tricky a bit, but according to my experience, 40 lb/ft and above should be fine with 45 degrees.

    When tightening an assembly, especially with TTY bolts precision is required and going over the specification is unadvisable.

    The old method of just using turning torque to set the tension of a fastener left a lot of potential for error. The low initial torque of the TTY fastener reduces error that can be caused by friction between the bolt head and the work, (45% of the effort) and in the threads (another 45 % of the effort) and focuses on simply setting the tension in the bolt by an angular measurement. When turned to a specific angle, the turning stretches the bolt into it's correct shape to set the proper tension for the assembly.

    Turning a fastener to a rotational torque higher than the initial specification can cause a TTY bolt to fail. When you look at a bolt, the picture you should put into your mind is a spring. Operate the spring in its normal range and it can be pulled and released and go back to it's original shape. But, if you stretch it too far it becomes damaged and will then no longer return to it's original shape. That's why TTY bolts cannot be reused and starting with a torque higher than the specification can damage the bolt. When done correctly the torqueing routine permanently stretches the bolt just short of the point that the bolt can fail. Any additional preload, or turning to great of an angle takes the bolt out of it's designed tension range.
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