Lug nuts are very small parts on your wheel, but they have the essential job of keeping your tires attached to the hub. Using the right amount of torque on these parts is vital to the safety of your vehicle. Understanding what torque is, what wheel lug nuts do, and how to check your lug nuts will help you maintain your vehicle’s safety.
What Is Torque?
Torque is a force that produces rotation. When it comes to the attachment of a car's wheels, torque is the amount of force that is applied to a lug nut when tightening it. Your vehicle requires a certain amount of torque to keep the wheels in place. Mechanics use a torque wrench to properly tighten the lug nuts on your car. This tool can be set to apply a specific amount of force and takes the guesswork out of torqueing the lug nuts properly. Using too much torque can damage the vehicle. Using too little torque can cause the wheels to come loose. You can find the amount of torque required for your vehicle in the owner’s manual or you can ask your mechanic.
Removing and Installing Lug Nuts
Removing lug nuts is typically much simpler than installing them. You can remove them using a lug, socket or impact wrench. If the goal is to remove a tire, you should set the parking brake, then, raise the vehicle with a jack before you take the lug nuts off. Your vehicle most likely came with a lug wrench, and a jack.
Installing lug nuts is a bit more complicated. First, make sure the threads of the nuts are free of oil, dirt and grime. To ensure an even distribution of pressure across the wheel mounting surface, the nuts must be installed in an alternating or star pattern. Tighten the lug nuts first by hand, then have a mechanic use a torque wrench to tighten to the manufacture’s specification. In an emergency, use the lug wrench to tighten the nuts until you can get to your mechanic.
Lug Nuts, Bolts and Wheel Locks
Wheel lug nuts come in different shapes and sizes, depending on the manufacturer and type. The best wheel locks function as lug nuts, but they require a special key to unlock the nuts to keep your tires from being removed.
Some European manufacturers use lug bolts instead of nuts. The bolts screw into a hole in the wheel’s hub instead of having a nut that screws onto a bolt. It can be a little more difficult to replace a tire using lug bolts, because you can’t hang the tire on the wheel studs to help you align it. If your vehicle has lug bolts, you should make sure you know how to change a tire in case of an emergency on the road.
What Happens When You Use Improper Torque?
Correct torque is vital to your car’s safety. These are the most common problems caused by improper tightening of your lug nuts:
- Stretched wheel studs - Overtightening the wheel lug nuts places too much strain on the wheel studs, which are the posts that the lug nuts attach to. This puts stress on the metal of the studs, which can cause a stud to break either during installation of a new tire or when you’re on the road. At the least, you might strip the lug nut, making it more difficult to change the tire next time you’re out.
- Unbalanced wheels - Too little torque can be just as risky as too much. Loose wheels wobble and stress the wheel studs, too. The wobbling can loosen the lug nuts until the wheel falls off the vehicle.
- Damaged brake rotors - Too much torque contributes to warping the brake rotors. This can cause your car to shake when you are braking, which leaves it difficult to control. It is also expensive to repair damaged brake rotors. Uneven torque on the wheels may also damage the brake rotors.
Good Car Maintenance Gives You Peace of Mind
If you have a blow-out on the road, don’t panic if you don’t have a torque wrench. Change your tire and tighten the lug nuts as best you can. Find the closest Sun Auto Service shop to have a technician check your tires with a calibrated torque wrench. Keep your car in the safest condition possible by understanding the importance of lug nuts to your driving experience.