Lug nuts are often overlooked, and many consider lug nut quality irrelevant. While they rarely affect how a car performs on the road, they are an important safety feature as they are the only thing keeping the wheels attached to the car. Although they’re designed to last a lifetime, they might need to be replaced.
In this article, we’ll talk about a phenomenon referred to as lug nuts swelling. We’ll talk about the causes, how to recognize lug nuts swelling, and the best thing you can do to prevent this from happening. If you suspect having this issue, here’s what you need to know!
What Causes Lug Nuts to Swell?
There are a couple of things that cause lug nuts to swell. Some of them are pretty obvious, while others are not so much. Here’s what causes lug nuts swelling.
Moisture
Moisture by itself won’t cause lug nuts swelling, but it can lead to corrosion, which is the main reason for this phenomenon. Modern vehicle manufacturers use two-piece lug nuts, which are made from a durable steel nut, and a decorative chrome cap.
The problem arises when moisture infiltrates between the lug nut and the decorative cap. This is especially noticeable in places with cold weather where salt is used on the road.
Heat
It’s known that metal reacts to heat, and there is plenty of heat in and around the wheels. Brakes generate high temperatures that often affect other nearby components. This includes your lug nuts.
Lug nuts can swell due to excess heat and sudden temperature changes only if they’re already damaged, or the lug nut caps are made from a low-quality metal. By expanding and reducing its size frequently, the decorative cap can become deformed, which directly leads to lug nut swelling.
Low-Quality Materials
Lastly, when the two-piece lug nuts are made from a lower-quality material, it’s a matter of time before a problem such as swelling will occur. Cars from several US and Asian manufacturers are among the most affected by this issue, but swelling also happens on cheap aftermarket lug nuts with decorative metal caps. This is why it’s important to invest in high-quality lug nuts, not just because of swelling, but because they’re holding your wheels attached to the car.
How to Tell Your Lug Nuts are Swollen?
There are two ways to tell if your lug nuts are swollen. But first, you need to assess whether your car has two-piece lug nuts. You can do this by inspecting all the lug nuts on your car, or by inquiring the vehicle manufacturer whether they’ve used this type of component on your vehicle according to the VIN number. You can also ask the manufacturer whether there were any recalls regarding swollen lug nuts.
Lug Nuts Are Visually Bulged
Visually inspecting your car’s lug nuts is the easiest way to tell if they’re swollen. You should focus on the side of the lug nuts because that’s where swelling would be the most visible.
It’s Difficult or Impossible to Fit the Right Socket Wrench
The most obvious symptom is the fact that you can’t use an adequate socket wrench to remove the wheels. If it’s even difficult to fit the socket on the lugs, it’s a clear sign that they are swollen to some extent.
In extreme cases, the socket won’t be able to fit the lugs at all.
What Can You Do to Prevent Lug Nuts from Swelling?
Unless your lug nuts are already swollen, there are a few things you can do to prevent this from happening. If they are, it’s recommended to replace them as soon as possible to avoid situations where you’re stranded on the side of the road with a flat that just won’t come off your car.
Avoid Using an Impact Wrench
Improper use of an impact wrench is a great way to damage your lug nuts. In many cases, people use the wrong torque setting on their impact wrenches. This, in turn, leads to damage to the decorative chrome cap.
This is especially the case when it comes to tightening the lug nuts. Instead, use the impact gun to mount the wheel and then use a torque wrench to torque the lug nuts to the manufacturer’s specifications.
Regular Inspection and Maintenance
Inspecting lug nuts won’t prevent them from swelling, but it will give you an opportunity to act when the problem occurs. Maintenance, on the other hand, can delay the swelling by removing excess debris from the studs. If you service your brakes on time, or have a habit of inspecting them, you should be fine. This can prolong the time before lug nuts become swollen, but it won’t prevent it completely.
Use the Correct Lug Nut For Your Car
Replacing two-piece lug nuts with corrosion-resistant ones is the only proven way to fully prevent this issue from happening. If OEM lug nuts are known to swell, you should pick an aftermarket alternative with corrosion-resistant features. This might change the aesthetics of the wheels, but it will prevent lug nuts from swelling, which is what matters the most in the end.
Alternatively, try to use OE lug nuts if you bought a car that came with a complete aftermarket setup. Lug nut swelling isn’t a common issue on European makes and models, so sticking to OE lug nuts should prevent any issues. Check our selection of lug nuts for a quality OE replacement.
How To Remove Swollen Lug Nuts?
A swollen lug nut won’t cause issues with driving, but it’s highly recommended that you replace them as soon as possible.
To remove swollen lug nuts by yourself, you’ll need to either use a hammer to seat the socket over the lug nut. This works when the swelling isn’t too bad. If it is, use a slightly larger socket.
A word of warning. Expect to have the lug nut stuck in the socket after removal. You’ll need a way to get it out of there that often requires a bit of force. Also, understand that your socket might get damaged in the process.
Get Quality Lug Nuts For Your Car
Most cars manufactured from 2010 forward include two-piece lug nuts. Some car brands are more prone to the lug nuts swelling issue than others, but you should check your lug nuts regularly just in case.
Here at eEuroparts.com, we offer a wide range of lug nuts for numerous European vehicles. Simply select the year, make, and model of your car, and you’ll find a product that fits your vehicle.
