Torque Wrench Selection and Accuracy Checks
Choosing a torque wrench whose range suits the specification, why crow-foot adapters change the reading, and when to stop trusting a wrench.
A specification is only as good as the tool applying it. Most torque wrenches are least accurate at the extreme ends of their range, and a wrench that has been dropped or stored under load may be reading anything at all.
Choosing the wrench and socket
Use a torque wrench whose working range places the target value away from the extreme bottom or top of the scale. A six-point deep socket that fully engages the nut reduces rounding. Extensions used straight do not normally change torque, but crow-foot adapters that change the effective wrench length require calculation. Return a click wrench to its minimum marked setting after use and calibrate it at the interval specified by its maker.
When not to trust the tool
If the only available wrench has been dropped, stored under load, or shows inconsistent clicks, use another verified tool. Wheel service is a poor place to test a questionable wrench. A smooth pull at the handle's marked grip point gives a more repeatable result than a jerk, bounce, or second click applied "for luck."
Values, sequences and intervals are vehicle-specific. Use the specification page for your exact year, engine and component alongside this procedure, and follow the manufacturer document it cites.
Torque Wrench Selection and Accuracy Checks FAQs
Do extensions change the torque reading?+
A straight extension in line with the drive normally does not. A crow-foot or offset adapter that changes the effective length of the wrench does, and requires recalculating the setting.
Should I store a click wrench at its setting?+
No. Return it to the minimum marked setting after use, and calibrate at the interval its manufacturer specifies.