Torque wrench types and how to use them
A practical guide from Caravan Information Services
Torque is a measure of force that causes an object to rotate on its axis. For caravanners, this means nuts and bolts.
Everything from the bolts that fix the tow bar in place to the ones that secure the caravan body to the chassis needs a specific amount of force to tighten correctly.
Caravanners usually focus on tightening wheel nuts or bolts. But torque is equally crucial for other DIY tasks, like fitting jacking point brackets to a chassis rail.
Why does torque matter?
How tight is too tight or not tight enough? After all, if you overtighten a caravan wheel, you might strip a thread or crack the bolt hole. But if you don’t tighten enough, the wheel can work loose.
Fortunately, wheel and hub manufacturers know precisely how much force is required and publish this information as a torque setting.
A conventional socket or wrench doesn’t tell you how much force to apply, so this is where a torque wrench comes in.
Torque wrench types
There are four wrench types:
- beam or deflection
- dial indicator
- clicker
- digital
The clicker-type wrench is considered the most practical choice for caravanners. Torque wrenches come in different sizes or maximum settings. But we recommend choosing one that torques up to at least 180 Nm (81 lb·ft).
How to use a clicker-type torque wrench
First, check that the wheel nuts or bolts are clean and rust-free and that the threads are in good order. Also, ensure the nuts or bolt heads aren’t rounded. Replace any that are in poor condition.
Check the torque settings in the caravan manufacturer handbook. The typical torque setting for steel wheels is 88 Nm (65 lb·ft), while for alloy wheels, it is 130 Nm (96 lb·ft). However, settings may vary depending on the wheel, hub and bolt sizes.
Double-check that you have the right-sized socket for the wheel nut or bolt.
Now, adjust the torque wrench to the correct setting by rotating the handle. Some wrenches have the settings engraved on the shaft, while others have printed sets behind a clear plastic strip. Some units also have a lock on the base, which fixes the setting, preventing anything from changing when in use.
Tighten each wheel nut or bolt diagonal until the torque wrench loudly clicks. Repeat the process once more, but not more than twice.
Top Tip: Always unwind the wrench’s torque setting to zero before stowing. Otherwise, the internal spring may compress and give a false reading next time out.
Well done! You now know why torque a torque wrench for wheel nuts matters and how to use a torque wrench. We recommend checking the settings whenever you prepare to embark on a journey. Wheel nuts and bolts can work loose over time despite tightening everything up correctly. Alternatively, consider fitting press-on nut and bolt position indicators. These low-cost plastic caps provide a quick visual reference to help you identify bolts that may have worked loose.
