Why wheel torque is important.
Pictured above: Wheel that was over torqued and required 2 hours of drilling to remove the wheel without damaging it.
It’s been that time of year for a few weeks now, and if you live in a colder climate you know what I’m talking about, winter tire season. Yes, the time of year many people dread, long wait times and for some the unfortunate news of a problem hindering the installation of their tires. One of the many reasons that could cause this is improper wheel torque, so it’s good to educate yourself. It’s sad to say but as someone who has worked in the automotive service industry for just over a decade it’s surprising how many little shortcuts some technicians/installers use. One shortcut many do is not properly torquing wheels onto vehicles and usually causing an over torque situation once the wheels need to be removed again. The worst of this I’ve witnessed personally many times where technicians claim they can “feel” the torque while using the impact gun. No matter what anyone claims to say and how much experience they may have there’s not way to “feel” the torque of an impact gun.
The next is not using torque sticks properly or not using the proper one. Somewhere along the line of automotive service history someone came of with the brilliant idea of using torque limiting sticks which are essentially a set of calibrated extensions put between the impact gun and the socket. These are somewhat the middle ground of doing it properly and doing it fast but they can be wildly inaccurate if not used properly. Torque sticks come in a variety of settings but come most commonly as ft/lbs in 60, 80, 90, 100, and 120. What many technicians don’t know is that torque sticks only limit a certain input range. For example, a 100 ft/lbs torque stick will limit an input of 200-350ft/lbs down to its rated 100ft/lbs. The problem lies in when you start to input more than 350ft/lbs which many of today’s impact guns are are easily capable of doubling. With the higher input torque the output will now also be higher but still reduced.
The proper way to tighten wheels is the use of a calibrated torque wrench and following the manufacturer’s procedures. This is the most accurate way to tighten wheel onto a vehicle but also takes the longest time to do. So now you know, obviously you’ll want to find a shop that follows the proper procedures but if you’re unsure of the place you’re getting tires put on ask them if they at least use torque sticks. Also, don’t forget to return for a wheel retorque, many shops offer it as a courtesy.