When checking the critical fastners what is the proper way? Do you just put the torque wrench on it and make sure it clicks at the correct setting or do you loosen the fastener first and then re-torque it? Or does it matter for these type of fastners?

Thanks

 

You just make sure it clicks at the proper setting. Of course, that doesn't tell you if it was over-torqued by the factory or your local mechanic, but that is all that is required to ensure the fastener is at least as tight as it should be.

For what it's worth, if you happen to use any kind of an adapter on a torque wrench, make sure it does not extend the length of the wrench. If you have to use a dogbone to get to something, put it at 90 degrees on the head of the wrench. There's actually a formula for ensuring you don't over-torque when using a dogbone, but I just use the 10% rule.

 

Phrogman's right- set the torque wrench to the minimum torque called for and make sure it clicks.

 

And make sure you don't accidentally use a ft lb wrench for inch pound fasteners. People have caused a lot of problems by using the wrong wrench.