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Torque wrench misuse

My first post in this section of the blog is dedicated to helping others on how to care for their tools, specifically the torque wrench.

We are not going to cover how to calibrate or take it apart, but rather what not to do.  As I was told by my former teacher (Mr. Ronchi), a lot of times it is not what you know that will matter, but what you know not to do with it.

Torque wrenches can vary in price, shape and technology, but the idea comes down to one thing, being able to accurately set a nut or bolt down to a specific tightening force.

After being used a lot of times, the torque wrench requires being calibrated for accuracy.  Keep in mind that just by regular use it will eventually require that type of service, it is normal wear expected in either the expensive top of the line tool and the regular off the shelf one.

There are speculations on how often you should get it calibrated, but most will agree that once a year is what a torque wrench requires to be always ready for the job.

If a torque wrench falls off your table, engine stand or any considerable height, you should not trust its reading anymore (not until it gets calibrated!).

Torque wrench taken apart

Where you store your tools and how you store them will tell how much you want it to be accurate when you need it, so torque wrenches need more care than other tools since it is a precision tool.

One very important thing about storing your torque wrench, and perhaps the most important tip on this post:  set it to zero once you are done using it.

Wrench set to 0 (rest)

Wrench set to 10 ft.lbs (not resting)

Note the 2 pictures above showing the arrow pointing to the 10 ft.lbs mark.  If you leave the tool as the second image shows, the inner spring will already be tensioned (do not store the tool at the that mark)

Torque wrenches similar to one in the pictures posted, have a spring inside, which is tensioned every time you set it to a specific torque reading.  Yes, the adjustable handle is supposed to be twisted countless times as you apply the tool in a job, but the spring inside is also supposed to be resting with no tension once you’re done, or else it weakens over time.

Spring found inside clicking-type torque wrenches

So if you’re working on an engine, or tightening lug nuts but you’re not finishing everything right away, and you’ll come back a few hours from now or maybe the next day, set it to zero before you go.

The spring tensioned will eventually fatigue with that bad habit.  Let’s say you need to tighten something down with 100 ft.lbs of torque, you will turn the handle to that reading.  As you apply force to the torque wrench, it will make the clicking sound much sooner than in should, let’s say at 70 ft.lbs of torque without you actually knowing it, because the tool was set to 100 ft.lbs.

This could mean the difference between a successful engine repair (changing a head gasket as an example) and a sooner or later job being redone with all the high cost of parts and labor.

So remember guys, after you’ve spent your hard earned money on parts for your car to make it faster and more powerful, or just to get it back in great shape again, don’t fail as a DIYer by using the tools improperly and improper tools.

Happy motoring!