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Old September 30th, 2018, 08:22 AM   #7
adouglas
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Get an inch-lb torque wrench to supplement your larger one. Choose the two wrenches so the upper end of one overlaps the lower end of the other.

You've likely overtorqued that bolt. Hopefully you haven't done any damage.

It helps to understand how "clicker" torque wrenches work. It's a misnomer. At lower settings, they do NOT click. They yield slightly. You're looking for that. Not a click or a sudden pop. A gentle displacement.

There are a few different ways to build these things. A concept diagram I created is shown below. The details of actual clicker wrenches vary but the principle is the same. Note that this is just my own understanding... I couldn't find an image online that accurately shows how I believe these things function.

Inside the wrench is a cup with a ball bearing in it (like a scoop of ice cream in a cone). There's a spring in the shaft of the wrench that presses on the ball bearing. When you crank up the torque setting, you're compressing the spring and pushing the ball more forcefully into the cup.

When you reach the specified torque the ball gets cammed out of the cup as shown.

At higher settings, the ball comes out suddenly. The click you hear is the head of the wrench slapping into the side of the handle. There is no "clicker" mechanism per se. The click is a side effect of the wrench yielding with enough force to make a noise.

But at low settings, the ball comes out gently. The exact same thing is happening, but the contact between the wrench head and the handle isn't sharp enough to make any noise.

Before you use the wrench again, I suggest you try it out to see what it feels like. Use the wrench to "tighten" an already-tight fastener that's installed with high torque... something like an axle nut on your bike or a lug nut on your car. Set the torque way too low, near the bottom of the range. You'll feel and see the yield, but there will be no sharp tactile sensation and no click. Now increase the torque to, oh, say, 30 ft-lb... still much lower than the spec of the fastener... and repeat. The wrench yields as before, but this time more suddenly and you can hear and feel the "click."

NEVER EVER use a torque wrench to loosen a fastener.
ALWAYS ALWAYS reset the wrench to its minimum setting before storage.
Use common sense. If you think "Hey, that should be tight by now," STOP before you overdo it.







PS: Shade-tree mechanic tip for those times when you don't have a torque wrench: When you've got the fastener finger-tight, do the last bit of tightening with just your fingertips. Press until you feel a good amount of pressure... until it hurts a bit or until your fingertip turns white (assuming you're white). One finger- about 10 ft-lb. Two fingers, about 20. Three fingers, about 30.
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