Lug Nuts Break Off While Driving (7 Reasons Explained + Fix)

lug nuts break off while driving

A lug nut or a wheel nut holds the wheel securely to your vehicle.

Can a Lug Nut Break?

Your vehicle’s lug nut is usually exposed to different elements. Plus, the nut handles an enormous amount of wear every day. Like any other mechanical component in your vehicle, lug nuts are prone to wear and tear. Once a lug nut has worn out extensively, it will eventually break.

When this happens, the wheel and tire will separate from your vehicle.

Why do Lug Nuts Break Off While Driving?

Improper installation

Many people use a spider wrench, impact gun, or breaker bar to install and tighten their wheel lug nuts. But, this is wrong and disastrous. Using these tools means that the wheel lug nuts will not be as tight as they are supposed to be. Therefore, they loosen or break off while you are driving.

The best way to tighten lug nuts is by using a torque wrench.

If you do not have a torque wrench at home or do not know how to use it, it is best to let a professional mechanic install the wheel lug nuts.

Over-torquing and under-torquing

Under-torquing wheel lug nuts reduce your tire’s overall security. Over time, these lug nuts will loosen or break off while you are driving. Most people do not understand that over-torquing or overtightening wheel lug nuts may also comprise them.

Over-torquing wheel lug nuts will overstretch the threads or studs beyond their responsive limit, reducing the clamping force. This often happens, especially if you or the mechanic repeatedly overtightens the lug nuts. It is also worth noting that over-torquing forces the lug nuts to crack or become cross-threaded.


Most manufacturers use aluminum alloys to make wheels today. They then secure them to vehicles using steel lug nuts. Aluminum and steel are different metals that contract and expand at different temperatures. A rapid decrease in temperature can cause wheel lug nuts to contract and become loose even if you have tightened them per the manufacturer’s recommendations.

This usually happens when a mechanic removes then reinstalls the wheels. The temperature outside is quite different from the temperature inside the auto repair shop or garage, so this difference causes the contraction and loosening.

So if the temperature inside the auto repair shop is too cold or too hot, it will likely cause the expansion or contraction of the wheel lug nuts.

Rusty wheel studs

Your vehicle’s wheel studs are made from stainless steel, preventing rust. However, this stainless steel is not fully immune to oxidation. If you drive your car over salty waters or sodium chloride, it will cause the wheel studs to corrode. This makes installing or removing wheel lug nuts difficult without damaging the wheel stud.

You should always check your wheel studs for rust at least once every year, especially if your vehicle is frequently exposed to salty water or sodium chloride. If you find some rust on the wheel stud, it is best to replace it with a new one.

Damaged threads

The threads of the wheel lug nuts are the same as that of the wheel studs. This helps secure your vehicle’s wheels once the lug nuts are fastened to the wheel studs. However, the threads may sustain damage due to improper installation or the cross-threading of the wheel lug nuts into the stud. This will cause the lug nuts to break off once fastened.

Cross threading of the lug nuts usually happens when the mechanic fastens a lug nut to the wheel stud at a wrong angle. If the mechanic uses a high-impact wrench to secure the lug nuts, it may also occur.

Hitting objects

When your vehicle’s wheel hits a hard object, pothole, or curb directly, the lug nuts will likely loosen or break off. Fortunately, many modern cars come with hub caps that prevent hard objects from hitting the wheel studs.

A missing lug nut

When a lug nut is missing on a wheel, it will exert uneven pressure on the entire wheel hub. If the lug nut is not replaced in good time, other lug nuts may start to loosen or break off due to the excess pressure.

What Happens When a Lug Nut Breaks Off?

When a lug nut breaks off, it will exert uneven pressure on the remaining wheel lug nuts. With time, the remaining wheel lug nuts will give in to this excess pressure and loosen or break off. This will create a serious safety situation for your vehicle, which you cannot ignore.

You should take your vehicle to a professional mechanic to replace the missing wheel lug nut before you cause an unnecessary accident on the road.

Can You Drive With a Broken Lug Nut? Is It Bad?

I don’t recommend you drive with a broken lug nut because it causes the vehicle to constantly wobble on the road, lose control, and roll over. This is dangerous for you and other road users. It is also worth noting that the uneven pressure of a broken lug nut can cause the wheel bearings and studs to wear out prematurely.

Most vehicles usually have four to six-wheel lug nuts. However, the number of wheel lug nuts on the wheel hub depends on whether your vehicle is a sports car, truck, sedan, or SUV. Since wheel lug nuts are customized to handle a certain amount of pressure, you will find out that bigger vehicles will have more wheel lug nuts than smaller ones.

Therefore, it is possible to keep driving your vehicle for a short period, even if you have a broken wheel lug nut. However, doing this increases the chances of exerting uneven pressure on the remaining lug nuts and misaligning or even separating the wheel from the vehicle while you are driving.

Repairing worn-out wheel studs and bearings requires much work and is much more expensive than replacing a broken wheel lug nut.

Therefore, if you notice that you have a broken lug nut, you should replace it with a new one as soon as possible to avoid causing an unnecessary accident or spending a lot more to repair damaged wheel bearings and studs.

What Do You Do When Your Lug Bolt Breaks Off?

  • If one of the wheel lug bolts breaks off while driving, you should find a safe spot away from the traffic and turn off the ignition. After doing so, inspect the remaining wheel lug nuts and ensure they are seated and tightened properly. If not, you can use a torque wrench to tighten them. This will secure enough time to drive your vehicle to an auto repair shop safely.
  • On the other hand, you can opt to drive home and soak the remaining lug nuts with WD-40. This will make it easier for you or the professional mechanic to remove the remaining wheel lug nuts once the time comes.

Can You Fix a Broken Lug Nut or Replace It? How Long Does It Take to Fix It?

Broken wheel lug nuts can only be replaced, not repaired. Replacing a broken wheel nut is a complex process that you should leave to a professional mechanic. Ensure that your mechanic has the right skills and knowledge, especially modern vehicle technology.

The process starts with removing the damaged wheel lug nut. Here is a step-by-step guide on how to replace a broken lug nut:

  • Park your vehicle on level ground and loosen the broken lug nut using a wrench
  • Take off the vehicle’s tire. After doing so, use a jack to raise your car and start the process of removing the broken lug nut. A damaged or broken lug nut will be rusty most of the time, so be prepared to deal with that.
  • Once you have identified the broken lug nut, use a low viscosity penetrating oil to spray it. This will loosen the lug nut and make it much to remove.
  • Connect a 12pt socket head to the broken wheel lug nut and remove it. Consider using a bigger 12pt socket head than the damaged lug nut to get a firm grip.
  • Once the socket head is in place, turn and remove it. After doing so, you can remove any visible rust from the wheel and install the new wheel lug nut.
  • Before installing the new lug nut, ensure that you lubricate the hole and fastener. Insert the lug nut as far as possible and fasten it using a torque wrench.

Removing a broken lug nut and replacing it takes approximately two hours.

How Much Does It Cost to Fix a Broken Lug Nut?

Lug Nut Replacement Cost

Lug Nut PriceLabor CostAverage Fixing Cost

The average cost of replacing a broken lug nut ranges between $102 and $122. The labor cost for the process ranges between $90 and $110, depending on where you live and the auto repair shop. Lug nuts usually retail at $12.

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