What Causes Tires to Wear on the Outside?

Most motorists only ask what causes tires to wear on the outside only when things have gone south. It is not supposed to be so. They rarely notice anything in the initial stage, which is bad. Such an act can lead to a catastrophic collision and drop expensive repair bills on the table.

That’s why you need to understand your tire tread wear pattern. Even a small outside tire tread wear can prevent the tires from hugging the road perfectly. It is important to note that the inability of a tire to maintain traction on certain pavements can lead to slippage.

Get this straight; do not allow tire wear to stay for an extended period because it’ll not only put you and other road users in unsafe conditions. It will also cost you more bucks. This is because tire wear becomes irreparable when it reaches a certain depth and needs a total tire replacement.

This article explains what causes tire wear on the outside edges and how to fix it. Let’s get the ball rolling.

What causes tires to wear on the outside

This section will focus on what will cause a tire to wear on the outside, regardless of the tire – front or rear.

what causes trailer tires to wear on the outside

Wheel Misalignment

Did you hit a speed bump or pothole lately? Or have you been involved in an accident? Did you mistakenly drive on a road’s hard shoulder? These are the common causes of wheel misalignment.

If you answered yes to any of the questions above, you likely have a misaligned wheel. This will cause sped-up tire tread wear on the outside. Note that everything might look alright at first, but as you drive for an extended period, you’ll experience tire wear on the outside edge mot.

The outer tire wear happens because the outer surface scrapes off itself on the road pavement as it travels on the road.

Broken Or Sagging springs

Vehicle springs play a critical role in supporting the entire car weight and absorbing excess energy from road shocks. This is possible because their anti-sway bar helps stabilize the car by shifting the wheel’s movement.

Because of how the manufacturers engineered the vehicle springs, constant heavy loads reduce or weaken their flexibility. You may notice a reduced height on coil springs and loss of arch on leaf springs. Vehicles with coil springs will experience accelerated outside tire wear because of loss of size due to aging.

Once a vehicle coil spring begins to lose its height, it’ll cause misalignment to the entire suspension system. The tires have no option other than to compensate by carrying the entire vehicle’s weight. The outcome is wear on the outside tire treads.

Improper inflation pressure

Improper inflation could be a reason for tire wear on the outside edge of front tires. Uneven, inner, or outer tire wear could be a result of improper tire inflation.

Therefore auto manufacturers specify both front and rear tire pressure needed for optimized driving comfort, gas economy, and handling. They also take tire wear into consideration.

Properly inflated tires help disperse vehicle loads, cornering force, and satisfactory braking on the tread. If the tire pressure is too high or too low, the tire contact patch will find it difficult to carry out its duty effectively.

Such a situation will quickly abrade the tire tread. As much as low tire pressure will cause toe-out wear on tires, too much pressure will cause the same effect. Hence, you should always maintain the specified tire pressure.

Damaged Ball Joints

Ball joints are critical suspension components. They serve as a connection that links the camber to the hub housing. Auto manufacturers engineered them to maintain optimum grip with suspension system components as the vehicle travels down the road. They also help offer vibration-free movement and give you confidence on the wheel.

Like other suspension systems, ball joints wear over time. As they wear off, the wheel goes out of alignment, and the tires point outwardly. Expert mechanics call it ‘wheel toe-out conditions.’

Tire wear because of a faulty ball joint can be hardly noticed, but it poses the same danger as other tire wears. For this reason, it is important to replace any faulty suspension components in your car before it damages other related components.

Bent struts or spindles

Struts and spindles are strong structural components of a vehicle. They work in harmony with shock absorbers and upper ball joints to maintain a vehicle-dampening impact and hold the entire suspension components together. They should work optimally for a comfortable ride.

In some vehicles, the upper end of a strut rotates to maintain the correct camber angle and wheel alignment. If the strut or spindle is bent, it will miss the specified alignment. The edges of only the front tires being worn are a sign of a bent strut and spindle.

The degree of the outside tire wear will depend on how little or how much the strut bent is. This means that a small strut bent will cause a few bucks to fix, while a severe bent will only require replacement.

How To Fix Outside Tire Wear?

Fixing outside tire wear requires different approaches, as there are several causes. Below are the steps you need to fix outside tire wear.

  • Getting wheel alignment
  • Replacing broken or sagging springs
  • Correcting improper tire inflation
  • Replacing worn ball joints
  • Repairing or replacing bent struts and spindles.

why does a tire wear on the outside

Getting wheel Alignment

Wheel alignment and balancing are necessary after working on some suspension components. Aside from that, expert mechanics recommend going for a wheel alignment every seven thousand (7,000) miles or twice a year. Consider decreasing the check-up duration if you have an older vehicle.

If your outside tire tread is wearing off because of misalignment, aligning the wheels could be all you need to fix the uneven or outside wear.

Replacing broken or sagging springs

If you notice you have sagged or broken springs, get a new one and replace them. It is a simple fix that you can carry out with DIY skills. If you don’t have the time or don’t trust your guts, seek a mechanic’s help for a professional fix. Whichever route you choose, be prepared to spend up to $450 for replacement parts.

Correcting improper tire inflation

It’s always good to maintain proper tire inflation because the vehicle’s entire weight rests on it. I recommend getting a portable tire inflator if you have over one car in your garage. With this, you can regularly check the tire pressure without constant visits to mechanic shops.

Maintaining proper tire pressure will halt or prevent accelerated outer tire tread wear. If you don’t see getting a portable tire inflator necessary, gauge your tire pressure at mechanic shops.

Replacing worn ball joints

If a worn ball joint is a culprit, replace it and align the wheels. If the outside tire wear continues, inspect and change the tie rods and control arms.

Faulty suspension components cause most outside and uneven tire wears complaints that I receive in my garage. That said, I recommend checking these components, especially the ball joints and control arms, before heading to other probable causes.

Reporting or replacing bent struts and spindles

Repairing faulty struts and spindles could be all you need to stop uneven and outside tire wear. If the bent is much, you may have to replace it.

You can replace this component yourself and save the labor charge. It is a no-complex fix.


Q: What causes rear tires to wear on the outside?

Several factors can cause rear tires to wear on the outside. We’ve outlined some of the reasons above. If you have outside tire wear on the rear wheels, it is most likely caused by a wheel misalignment, bent struts, and spindles.

Other probable causes include worn-out camber or control rod bushings and sagged springs underneath the vehicle. When tracking down the culprit, do not forget that a worn wheel hub bearing can cause accelerated uneven and outside tire wear.

Q: Can bad shocks cause tire wear?

Shocks perform several essential functions on vehicles. It connects the car frame with the wheels. It limits vehicle movement by pushing the wheels against the pavement surface for improved traction.

It improves drivers’ control and increases satisfactory braking. It also halts sped-up wear on airbags, springs, and other more essential (and expensive) suspension and steering components.

If this component fails, it’ll cause premature wear on tires. A failed shock can cause cupping and other premature or uneven tire wear.

Q: What happens if you over-inflate your tires?

Over-inflation on tires makes them more vulnerable and easy to damage. If tires are filled to their maximum capacity, they become more inflexible and stiff. This exposes them to damage when you hit potholes or are involved in a collision.

When traveling with an over-inflated tire, you’ll feel every dip and bump on the road. You’ll agree; this is not good for a comfortable ride.

Too much air or nitrogen pressure on the tire will distort the shape of the tire, leading to decreased traction and accelerated tire wear on the center. The tire may wear quickly, depending on the tire circumference.

Q: Where do tires wear on the road?

It is important to understand how to read toe out and toe in tire wear patterns. Tires can wear on various spots depending on the causes of the problem. Here are some of the places a tire can wear on the road;

  • Inner or outer shoulder wear: misalignment mainly causes this.
  • Center tire wear: Overinflation is the primary cause.
  • Edge shoulder wear: under-inflation causes edge shoulder wear.
  • Cupping: Suspension issues.
  • Diagonal tire wear: It means you need a tire rotation.

I recommend you read the tire wear tread pattern to understand this clearly.

Final words

When you track what causes tires to wear on the outside of your vehicle, follow the repair procedures above to get it fixed. Sometimes, tire rotation or wheel alignment may be all you need to resolve the issue. These will cause you little to nothing in your pocket.

Suppose other probable causes like sagging springs, worn control arm bushings, bad ball joints, shocks, bent struts, or spindles are the culprit; consider spending $400 to $600 or even more. Whatever the culprit is, please do not allow it to stay for an extended period as it can cause the tire to burst on the road. And this poses a danger to the life of the driver, passengers, and other road users.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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