Over the past few weeks we’ve looked at a that can save wrenching time, a to bust loose a lug nut when your impact wrench won’t do the job and a to help load vehicles onto trailers. This week’s cool tool is a set of torque limiting extensions to make wheel mounting quick and safe.

This suggestion comes from reader mike937, and you may have even seen these in use at your local tire shop. These are also often called torque sticks.

The safest way to install a wheel onto a car is to ensure that each lug nut or bolt is properly torqued. This ensures that a vehicle may not lose a wheel due to it being under-tightened and the hub’s studs don’t break or strip from being over-tightened.

I’ve seen many DIY wrenchers and even some tire shops just zip lug nuts or bolts on for an arbitrary amount of time using the biggest impact they have, then calling it a day. Sure, this is the fastest way to mount a wheel, but it can lead to unintended results. In one case, I broke a bunch of tools trying to do the brakes on my neighbor’s Chrysler Town & Country because I couldn’t get the wheels off.

What happened? The shop that installed her new tires tightened a few of the lug nuts to what felt like 1,000 lb-ft when the van only required 100 lb-ft.

There is a better way to install wheels both quickly and accurately: using torque limiting extensions.

So, how do these tools work? It comes down to how they’re made. The extensions are made of sprung steel that can twist to a certain degree. Each extension has a torque limit. Torque limiting extensions are designed to be used with an electric impact wrench or a pneumatic impact wrench. When you reach the stated limit of that extension, it’ll begin to twist to prevent further tightening of the bolt or nut. The end result is that if you’re using an extension that tightens to 90 lb-ft, the nut or bolt should be tightened to about 90 lb-ft. This is why each extension is a different thickness.

These extensions aren’t perfect, so don’t be surprised if an extension rated for 90 lb-ft only tightens to 87 lb-ft. What you’re supposed to do is finish the job using a torque wrench.

This YouTube video from shows the proper way to use these tools.

Be careful using a powerful impact with a lower-rated torque extension. Feed an extension too much torque and that steel can snap.

These tools also aren’t too expensive. They can get as low as $50 for good quality sets.

Do you know of a weird or unique but must-have tool that every wrencher should have? Do you want to see us put a type of tool to the test and see how it performs? Shoot me an email or drop it down in the comments!