Everything one needs to understand and know about steering knuckles.

The steering knuckle is loath of steel with various protruding arms located right behind the front wheels. It helps in connecting the wheel hub which is also called a Spindle to the suspensions of the vehicle. The caliper of the disc brake mounts the knuckle. 

But what is a steering knuckle and what’s its role in a vehicle? 

The steering knuckle is the last part of the steering system, it is also called a wheel carrier or an upright. But what is its role? 

The steering knuckle is attached to both the ends of the frontal wheels and is connected with the steering wheel. It helps in turning the wheels when you turn the steering wheel. 

How does the wheel carrier help in turning the vehicle? 

Just imagine if you are driving a race car that runs at almost 250 km per hour how precise the steering mechanism has to be? Similarly, if you are driving a truck how precise the turning mechanism has to be? Any small defect in the turning mechanism of the vehicle can lead to a cascade of issues. 

So how does the steering knuckle help in turning a vehicle? 

The steering knuckle’s top and bottom points are connected with the suspension system with the help of pivots which are called “Ball joints.” The crucial component in turning the wheels is Ball Joints they are the mediator of pivoting the knuckles left or right. 

Another imperative characteristic of the ball joint is keeping the steering knuckle straight up in a vertical position which is another critical criterion for the vehicle to turn smoothly and efficiently. The steering knuckle has lateral arms which connect to the tie rod. 

When you steer the tie rod either pull the lateral arm inward or push it outward which completely depends on the direction where you have steered the wheel. 

The tie rods are located on both sides of the vehicle, when one tie rod pushes the lateral arm outward the other tie rod simultaneously works in the opposite direction by pulling the lateral arm inward. This turns the knuckles and front wheels in unison. 

Just imagine if you are driving a race car at 270 km per hour and you have to take a sharp turn and the steering knuckle is not in a vertical position because the ball joints are not damaged or the tie rods aren’t working properly then how cascading that would be. 

Hence make sure if you are driving a race car, a truck, or even a highway car to maintain your steering knuckles. 

What if a steering knuckle is broken? How can it lead to catastrophe?

The steering knuckle is normally very sturdy and strong and in normal use, they are long-lasting, and mostly they last as long as the vehicle is in decent condition. However, any sort of accident like a minor collision, hitting a really big pothole, or sliding into a curb can incite severe damage to the steering knuckle.

If you damage the knuckle badly or if it’s broken then it is obvious that your vehicle would be disabled. 

When the steering wheel is bent or slightly damaged the vehicle might seem like it can be driven, but in reality, it’s the worst case to drive your vehicle with a damaged steering knuckle. If driven with damaged knuckles certain things may go wrong like: 

  1. The wheel alignment is completely out of the picture which leads to wear and tear in the wheels and causes extremely poor handling. 
  2. The damaged knuckle causes extreme pressure on the ball joints which can incite the ball joint to break suddenly. 

Once the ball joint is broken then steering is out of the question and you may lose control of the vehicle which can cause a severe accident. And if you are driving at a very high speed or off roads then the broken ball joint can even take your life. 

So if you suspect any issues in your steering knuckle then make sure you get it inspected by a professional and resolve the issue. 

How to know if the steering knuckle is hampered? 

The traditional way to understand if the steering knuckle is damaged is to remove the wheels, lift the car and visually detect the issue, but that sounds extremely time-consuming and difficult if you are on your own. 

So what are other ways or symptoms which can help us to understand steering knuckle damage symptoms? 

  1. One of the front wheels appears to be more tilted than the other one 
  2. You hear a squealing noise when you are turning the vehicle. 
  3. The vehicle pulls sideways either left or right. 
  4. The steering wheel is hard and crooked when you are driving straight. 
  5. The vehicle corners pretty badly when you are steering in one direction than the other. 

However, the best way to inspect a broken steering knuckle is to visually see it or by comparing it with the other steering knuckle. 

 How do you deal with broken steering knuckles? 

Steering knuckles are sturdy and heavy-cast made with thick aluminum or steel. Hence when they are damaged or broken repairing them is almost impossible, hence they are irreparable and they need to be replaced. 

If the knuckle is made up of steel then it can be repaired with the help of magnetic particles, dye penetration, and ultrasonic testing. It can also be well repaired under controlled ambient conditions, filling the original hole and remaining the bolt hole and stress relieving it locally. 

The average cost for the replacement of the steering knuckle varies from $664 to $710, excluding the labor costs which are also high ranging from $200 to $500. 

The cost changes from vehicle to vehicle and completely depends on the complexity and type of vehicle. For example, the replacement cost for a race car would be on the higher side as compared to normal vehicles. 


If you want to know more about steering and suspension in various vehicles, especially Off-road vehicles then please don’t hesitate to visit RPM STEERING.COM. Our designs are based on Aluminum hence we are also known as the Aluminum Company. 

Get Product Updatesincluding Sales and Deals