Knocking Noise From Front Wheels When Driving –Causes & Fixes

Cars make noise under normal operation. Every car has a unique noise and you will accustom to these noises with time. A vehicle engine, for instance, makes a little hum sound when the engine is running.

The moment you notice a strange noise from anywhere around the car, it’s a sign of a faulty system component. Banging, squeaking, squealing, clicking, clunking, knocking, and grinding noise are all indications of system component malfunction.

In this article, we’ll be looking at the causes of knocking noise from front wheels when driving. We’ll also outline repair procedures to track and fix the noise.

What Causes Knocking Noise From Front Wheel When Driving?

There are several issues that may cause a strong knocking noise from the front wheels when accelerating. These issues are not far from the steering racks, brakes, and front suspension components.

knocking noise when driving straight

Broken strut or strut mounts

The strut mount connects suspension system components with the vehicle frame. It minimizes tire vibration because of road conditions and stabilizes the steering system control. A strut mount is connected to a strut/shock absorber and the vehicle frame.

If the strut mount fails, or breaks, it will cause a banging or strong knocking noise in bad road conditions. It’ll also cause occasional knocking sounds when driving slowly on a straight pavement.

Broken sway bars

Sway bars are essential vehicle suspension components that prevent rolling when taking corners. They balance the vehicle’s weight. I bet you know what it means to drive with broken sway bars.

If you have a broken sway bar in place, you can flip your vehicle when speeding up on a bending corner. Since the sway bars balance the vehicle weight from one side to the other, they are subject to stress. As a result, they can break.

When they break, it’ll cause a knocking sound under the car when driving, especially on a bumpy road.

Loosen lug nuts

Lug nuts, also known as wheel nuts, are what hold the tire with the wheel hub. When working on the suspension system that needs taking off the tires, the technician will remove the lug nuts. One can swap tires because of a tire rotation or flat tires. 

If you have recently worked on the suspensions or swapped your tires, and notice knocking noise when driving at high speed, check the lug nuts. If the lug nuts are not properly tightened, they’ll project wheel vibration or wobble when driving at high speed.

The worst part is, the longer or faster you drive, the more it loosens. If not tightened on time, it can cause the tires to pull off. You don’t want this to happen because it can endanger the life of the driver, the passengers, and other road users.

In most cases, it will cause uneven tire wear and damage to suspension components. Therefore, if you notice you have a loose lug nut, don’t drive any further. Park your car in a safe spot and re-tighten the lug nuts.

Bad bushings

There are several bushings in a car. They’re installed to help properly align the wheels. Aside from the aligning purposes, they stabilize the suspension components and keep them in check.

Manufacturers produce bushings with rubber materials. Because of the rubber materials used, they wear over a long period, especially when they’ve suffered too much stress. When they wear down far enough or break, it’ll project a knocking noise when not accelerating or braking.

The knocking noise is coming out because two or more metal components are rubbing against each other without the bushing to buffer them.

Bad tires

Tires play a significant role in the movement of every car. Without the tires, a vehicle cannot move because they are what make contact with the road. So misaligned, imbalanced, or bad tires will cause a bumpy feel on the road. It can also cause occasional knocking sounds from the wheels when it rubs against suspension components.

Damaged wheel bearings

Wheel bearings are seen in wheel hub units. They facilitate the wheels to spin freely. When a wheel hub starts failing, it’ll cause a humming noise when coasting down the road. The noise will intensify as the RPM increases. The bearing will keep damaging as you continue driving with it.

A severely damaged wheel bearing will not allow the wheel to spin freely. If the bearing scatters inside, it may cause a knocking noise when driving straight.

Damaged control arms

A control arm is an integral part of a vehicle suspension component. They go up and down as you drive, thereby keeping your car steady. They offer you a smooth and seamless driving experience by absorbing vibrations as the tires travel in bumpy or uneven road conditions.

If the control arms break or the bushings wear out, you’ll have an extremely rough driving experience behind the wheels. The tires may bounce off the road as they hug bumpy or bad pavements.

Bad control arms on the front wheels will cause a rough driving experience and some knocking noise from the front wheels when driving slowly.

Faulty ball joints

Suspension components are interconnected with one another. These components work in harmony to absorb road vibration and offer a smooth driving experience. The ball joints connect the wheels to the suspension systems.

They allow the wheels to rotate properly when turning left or right. If these ball joints start wearing off, they will start causing banging, grinding, or knocking noise when turning the steering wheel. The noise will intensify as you turn the steering wheel fully to the right or left. 

Axle problems

The entire weight of a vehicle rests on the axles, and the front weight of a car rests on the front axle. A vehicle axle is engineered to stay sturdy and last the lifespan of a car. By default, you shouldn’t worry about maintaining or repairing it.

In any case, the axle can be damaged and not reach the lifespan of a car. This can happen when you have an accident or mistakenly hit a big porthole.

Of course, an axle can be a manufacturer’s defect. There are cases where manufacturers recall some cars for this reason alone. Such cases usually make the axle unable to withstand the entire weight of the vehicle for a long time.

Unfortunately, a bent axle cannot be repaired. When an axle is bent, the tires will not be able to hug the road evenly any longer. This can cause uneven outside tire wear, turning issues, and knocking sounds when driving over bumps.

How To Fix Knocking Noise From Front Wheel When Driving

Having seen what would make a knocking noise on front wheels, let’s look at how to fix them. Fixing knocking noises from the front wheel when driving can be tasking and challenging. It involves following several diagnostics methods to track and fix the annoying knocking sound. Let’s look at the steps below.

knocking noise when driving straight

 Bounce the front of the car

The first step I recommend when fixing frontend noises on a vehicle is to bounce the vehicle. You’ll need an assistant to do this. Open the hood and have the assistant press down the hood and release it repeatedly. Keep doing this until the suspension starts working.

While bouncing the vehicle, examine the strut and strut mounts. A failed or broken strut mount should be making excessive movement. If you can’t figure out if there is excessive movement from the strut mounts, go old-school fashion. It’ll also help you figure out issues on the strut and other suspension components like control arms, 

Get a giant screwdriver and place the handle edge on your ear and the other end on the suspected components. Have your assistant bounce the vehicle again. You should hear excess noise on the failed component.

This method works almost as well as a mechanic’s stethoscope. Did you detect any failed components? If there’s nothing obvious, let’s proceed to the next step. Get a floor mat and lie underneath the vehicle.

Wiggle the steering wheel

You can use this method to pinpoint failed steering components like the tie rods and steering knuckles. You might be wondering, why this method? Do the steering components make knocking noises?

Failed steering system components make clunking sounds. So, let’s check these components as well.

Turn the ignition to the ‘ON’ position. Have your assistant sit on the driver’s seat and turn the steering wheel vigorously. Check the suspension components for excessive movement. You can also do this by turning the steering wheel all the way left and right.

 Wiggle or shake the vehicle

This method will help you detect knocking, clunking, and banging noises underneath the car. Get two assistants and have them shake the front vehicle roof. One should stand on the driver’s side while the other on the passenger’s side.

While they shake the vehicle with force, lie under the vehicle with your underhood work light. Check all the components that we mentioned above that should be causing knocking noise. These include the ball joints, control arms.

Alternative sources

Sometimes, what we call knocking noise could be coming from alternative places. Now, you need to check the exhaust systems – the muffler, catalyst converter, tailpipe, and head pipes. Check the connections and hanger that holds them in place. 

If you have a loose hanger, they can be hitting on the frame, or against other components. Allow the vehicle to cool down to a point you can safely hold the exhaust pipes. Wiggle the pipes and see if it’ll replicate the knocking sounds.

Renewing the vehicle

While it’s possible to repair worn-out control arms and bushings with shims or screw in a bolt in a wiggling knuckle, the only real fix is a replacement. While this may be quite costly, it’ll give you a noiseless driving experience for a longer period.

Whatever the cost is, follow a more prominent way to fix it. Yes, it may be costly, but it’ll be worth it in the long run.

Check the lug nuts and re-tighten them if they are loose. Check the tires for uneven wear and change them with new sets if necessary.

FAQs

Q: What is a clunking sound at the front end?

Clunking sound in the front end of the vehicle means a component is hitting something hard on an object. One of the common causes includes failing ball joints, bad tie rods, worn-out control arms, etc. Usually, a clunking sound intensifies or more frequently as time goes on.

Q: Does a bad wheel bearing make a knocking sound?

A worn wheel bearing is a great deal. If you ignore it for a longer period, the noise will intensify. In a worst-case scenario, it can cause the wheels to fall off. Of course, you know what that means. It will lead to a catastrophic collision that’ll endanger your life and that of other road users.

When a wheel bearing fails, it starts making unusual vague noises. Some of these noises include humming sound, grinding noise, crackling noise, rumbling/growling noise, and clunking/knocking sounds.

Q: Why do I hear a knocking sound when I drive?

Do you hear knocking sounds from underneath your vehicle? Does it happen when slowing down, accelerating, braking, or idling? Whatever the reason is, you can fix it. Some causes are easier and less expensive to fix than others.

A knocking sound from underneath a vehicle means you have

  • Worn out control arms
  • Misaligned tires
  • Axle problems
  • Loose lug nuts
  • Strut and strut mount issues
  • Bad ball joints
  • Worn out wheel bearings and
  • Loosen hangers and connections underneath a vehicle.

Q: Can a strut make a clunking noise?

A clunking/knocking sound when driving over bumps means you have bad or failed suspension components. Metallic clunking shows something is hitting on hardware.

A loose mount will cause excessive movement between the attaching components and the bolt. A worn strut mount will allow the shock to go up and down, causing a clunking noise.

Q: Is it safe to drive with knocking noise from the front wheel?

If you hear a clunking sound coming from the front of your vehicle, do not drive with it. Minor and more severe damage to the suspension systems can cause clunking sounds on a vehicle. Driving with it means you’re putting your life, that of passengers, and other road users at risk. There are several reasons your car may be clunking. Whatever the reason may be, fix it before hitting the road.

Q: Do ball joints make a clunking noise?

Of course, bad ball joints make a clunking noise. One of the most noticeable and common signs of a failed ball joint is clunking noise. A bad ball joint will make a rattling noise inside as it wears off. If you continue driving with it, it’ll intensify to a clunking noise.

Final words

The unusual sounds you hear from a vehicle are one of the most noticeable and common signs you’ll see when a component wears off. You need to know the normal sound your vehicle makes when driving so you can figure out when something is going wrong.

Knocking noise from front wheels when driving shows there’s an underlying issue with the suspension components. This article has outlined the causes of these sounds and how to fix them. Follow the instructions in this article to fix knocking noises in your vehicle. 

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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