When your vehicle’s suspension starts to feel off maybe you hear a knocking sound over bumps or your steering feels loose it’s often due to worn control arm bushes. These small but mighty components are essential to keeping your wheels aligned, your ride smooth, and your car safe to drive. But here’s a common question many drivers have: If one control arm bush is worn out, do I really need to replace both sides?
The short answer is yes, and this post explains why. Replacing both the left and right control arm bushes at the same time isn't just about symmetry it's about ensuring optimal performance, safety, and cost efficiency.
Understanding the Role of Control Arm Bushes
Control arm bushes are rubber or polyurethane mounts located at the pivot points of your vehicle’s control arms. They connect the control arm to the vehicle’s frame or subframe, cushioning the movement between the two. These bushes allow limited movement in the suspension system, helping absorb shocks and bumps from the road while maintaining proper wheel alignment and suspension geometry.
In simple terms, control arm bushes are responsible for:
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Smoothing out road vibrations
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Absorbing impacts from potholes and rough terrain
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Minimising metal-to-metal contact
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Keeping your wheels pointed in the right direction
When they wear out, the result is increased vibration, noise, imprecise steering, and uneven tire wear.
What Causes Control Arm Bushes to Wear Out?
Like any rubber component exposed to constant motion, heat, and road conditions, control arm bushes eventually degrade. Common causes of wear include:
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Heat and friction: As the rubber flexes repeatedly, it loses elasticity and begins to crack.
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Age and time: Even with gentle driving, rubber bushes harden and deteriorate over time.
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Moisture and road grime: Dirt, salt, and water can degrade the rubber and corrode nearby metal components.
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Harsh driving conditions: Off-roading, towing, or driving on poorly maintained roads accelerates bush wear.
Once the rubber cracks or deforms, the bushing loses its ability to properly absorb movement. This leads to looseness in the suspension, misalignment, and noisy operation.
Symptoms of a Worn Control Arm Bush
Worn control arm bushes often produce noticeable symptoms, such as:
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Clunking or knocking sounds over bumps or during braking
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Loose or vague steering feel
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Vibrations in the steering wheel
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Uneven tyre wear
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Poor alignment or vehicle pulling to one side
These symptoms usually show up gradually but can lead to serious handling problems and premature wear on other suspension components if ignored.
Why Replacing Both Sides Is Best Practice
Now that you understand the importance of control arm bushes, here’s why it’s generally recommended to replace both the left and right bushes at the same time, even if only one side is currently showing signs of wear:
1. They Wear Out at a Similar Rate
Both sides of your suspension system experience the same general forces road bumps, braking loads, and vehicle weight. So if the bush on the left control arm has worn out, the one on the right is likely close behind. Replacing only one side means the other could fail soon after, leading to another round of repairs.
It’s like changing one worn tyre while leaving the other old one on the same axle it can cause uneven handling and premature wear.
2. Consistent Handling and Performance
Replacing only one control arm bush can result in an imbalance in how your car handles. A fresh, stiff bush on one side and a soft, worn one on the other can cause:
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Unstable steering
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Uneven load distribution
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Braking instability
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More body roll on turns
Replacing both sides ensures balanced suspension geometry, improving overall handling, safety, and driver confidence especially at higher speeds or on wet roads.
3. Labour Efficiency and Cost Savings
From a practical standpoint, much of the labour involved in replacing control arm bushes raising the car, removing the wheels, accessing the arms is the same whether you replace one side or both. By replacing both at once, you save on labour charges and avoid having to return to the workshop later.
In the long run, it’s more cost-effective to do the job properly once than piecemeal over time.
4. Reduce Downtime
If you only replace one side and the other fails soon after, you’ll need to take your car off the road again, schedule another service appointment, and possibly deal with unexpected symptoms. Doing both sides at the same time minimises future inconvenience and keeps your vehicle road-ready.
5. Avoid Extra Wear on New Parts
When you install a new bush on one side and leave the worn one on the other, the added movement from the worn bush can cause excessive stress on the new component, shortening its lifespan and reducing its effectiveness. Installing both ensures your new parts wear evenly and last longer.
When It Might Be Okay to Replace Just One Side
There are a few situations where it might be reasonable to replace just one control arm bush:
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The other side was replaced recently, and is still in excellent condition.
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You’re in an emergency situation and can only afford or manage one side for now.
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The vehicle has very low kilometres, and one side was damaged from a specific incident (e.g. hitting a pothole).
Even in these cases, it’s important to plan for replacing the second side soon. Think of it as a temporary solution, not a long-term fix.
Do Control Arm Bushes Come in Pairs?
Most aftermarket and OEM suppliers sell control arm bushes individually, but many brands (like Transgold) offer left and right kits for convenience. At Universal Auto Spares, we always recommend replacing control arm bushes in pairs and offer complete kits to match.
These kits are:
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Pre-tested for Australian conditions
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Made from durable rubber or upgraded polyurethane
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Designed to fit your specific make and model with OEM precision
Professional vs DIY Replacement
Replacing control arm bushes can be a DIY project if you have the right tools, but it's not always straightforward. Some control arms need to be pressed out using a hydraulic press or special bushing tool. Others may come as part of a complete control arm assembly, which is easier to install but more expensive.
Whether you choose to DIY or use a trusted mechanic, the key is quality parts and correct installation. A poorly installed bush can cause more problems than it solves.
Final Thoughts
Control arm bushes are small parts with a big job. When they wear out, your whole suspension system suffers affecting comfort, control, and safety. If one side is worn or damaged, the best course of action is to replace both left and right sides at the same time.
Doing so ensures:
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Balanced suspension performance
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Longer-lasting results
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Fewer trips to the workshop
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Better value for your money
Need New Bushes?
At Universal Auto Spares, we stock a wide range of control arm bush kits and complete control arms for popular makes and models including Toyota Hilux, Ford Ranger, Mazda BT-50, Mitsubishi Triton, and more.
✅ Affordable, OEM-quality parts
✅ Fast shipping across Australia
✅ Expert support and fitment advice
