HOW ITS MADE - Front Lower Arm Bush - Range Rover, Sport and Discovery 5

May 24, 2023

HOW ITS MADE – Front Lower Arm Bush – Range Rover, Sport and Discovery 5

The Land Rover Discovery 5 and Range Rover / Range Rover Sports have an Achilles heel – FLAB!

When it comes to off-road performance and driving comfort, a reliable suspension system is crucial, and this is where Polybush steps in.
Polybush is a renowned manufacturer of high-quality suspension bushings, offering improved durability, performance, and ride quality. Dealing with some of the largest Land Rover specialists in the country, when we’re asked to manufacture a solution for the well-known problem with the Land Rover Discovery 5, Range Rover and Range Rover Sport we jumped to action!

Frustratingly for owners, the problem on the Discovery is the Front Lower Arm Bush (Part of LR113306) which consistently fails at very low mileage – some at less than 30,000 miles!
As the bush is not available on its own, the only option is to replace the front lower arm in its entirety, which can be a huge problem for owners and garages alike.

The Culprit

When a suspension bush fails, it can negatively affect the vehicle’s performance, safety, and ride quality, some of the common results of bush failure are:

Increased Vibrations: A failed bush can result in increased vibrations felt through the steering wheel, floorboards, or seats. This can make the driving experience uncomfortable and reduce overall ride quality.
Poor Handling and Stability: Suspension bushes play a crucial role in maintaining proper alignment and control of suspension components. When a bush fails, it can lead to excessive movement or play in the suspension system, causing a loss of stability, poor handling, and compromised vehicle control.
Excessive Tire Wear: Faulty bushes can affect the alignment of suspension components, leading to uneven tire wear. This can result in premature tire degradation, reduced traction, and compromised safety.
Increased Noise: Failed bushes can cause clunking, knocking, or squeaking noises as the suspension components move and make contact with each other. These noises can be irritating and indicate underlying issues with the suspension system.
This can be a sign of worn suspension bushes
Reduced Braking Performance: Suspension bushes contribute to maintaining proper suspension geometry during braking. When a bush fails, it can adversely affect braking performance, potentially leading to longer stopping distances and reduced overall braking effectiveness.
Altered Steering Response: Failed bushes can impact the vehicle’s steering response and precision. This can result in a delay or imprecise steering input, making it harder to control the vehicle accurately.
Safety Concerns: A failed bush can compromise the overall safety of the vehicle. The excessive movement or play in the suspension system can affect the vehicle’s ability to respond to sudden maneuvers or road irregularities, potentially increasing the risk of accidents.

To develop a replacement product we need to have an understanding of the original suspension Bushes

Step one of the design process is to understand how the Original Equipment bush fits into the suspension arm, then how the arm fits into the chassis, also taking into account bracketry and space available, this is done by looking over a vehicle in the flesh and taking measurements and cross-referencing O.E diagrams, we then test an O.E bush in its housing, radially, axially & angularly taking into account the original hardness of the bush.

Understanding the original bush, how it acts and indeed how it fails, is key to designing a product that not only takes what the manufacturer wanted, but allows us to improve its durability and functionality for the end users, taking into account performance and comfort requirements.

: Measuring Original Bush

: Hardness Testing Original Bush

Polybush’s Design Approach:
Polybush employs a meticulous design approach to ensure their suspension bushes meet the demanding requirements of Land Rover Discovery 5 owners. Here’s an overview of their design process:

Material Selection: Polybush utilizes high-grade polyurethane, to create our suspension bushes. Polyurethane offers excellent durability, resilience, and resistance to chemicals, oils, and environmental factors. This choice ensures a longer service life and enhanced performance compared to the stock rubber bushes.
Precision Engineering: Polybush’s engineers employ cutting-edge design tools and techniques to develop suspension bushes that precisely fit the Land Rover Discovery 5. By utilizing computer-aided design (CAD) software and 3D modeling, they can optimize the shape, dimensions, and geometry of the bushes, guaranteeing a perfect fit.
Performance Enhancement: One of the key aims of Polybush is to enhance the vehicle’s performance both on and off the road. Through careful design and testing, they optimize the stiffness and compliance characteristics of the bushes. This helps in reducing body roll, improving steering response, and enhancing overall stability, resulting in a more controlled and comfortable driving experience.
Durability and Longevity: Polybush focuses on creating suspension bushes that can withstand the rigors of off-road adventures and everyday driving. Their bushes are engineered to handle extreme loads, resist abrasion and wear, and maintain their performance even in challenging conditions. This durability ensures that your Land Rover Discovery 5 remains reliable and capable for years to come.

Benefits of Polybush Suspension Bushes for the Land Rover Discovery 5: Investing in Polybush suspension bushes for your Land Rover Discovery 5 offers numerous benefits:

Enhanced Off-Road Capability: The improved suspension performance and stability provided by Polybush bushes contribute to better off-road traction and control, allowing you to tackle challenging terrains with confidence.
Superior Ride Quality: Polyurethane bushes reduce noise, vibration, and harshness (NVH), resulting in a smoother and more comfortable ride for both on and off-road driving.
Increased Durability: Polybush suspension bushes are designed to outlast standard rubber bushes, offering a longer service life and reduced maintenance costs.
Easy Installation: Polybush provides a direct replacement for the original bushes, ensuring a straightforward installation process without the need for modifications.

Polybushes fitted to the L494

Long Term Testing:

As part of our testing program all of the products we manufacture are tested over many years, in this case, the test car is owned by one of our directors, so not only was it the original test vehicle, but it is also the long term test vehicle – Used on a farm, the vehicle in question, a Range Rover L494 goes offroad, pulls heavy trailers, as well as driving long distances over the UK and Europe. So three years later, we brought the Rangey to HQ to check everything was running as well as it should.
As you can see from the pictures below, aside from the underside of the vehicle being absolutely covered in road & farm grime everything looks as good as it should, with nothing out of place whatsoever.

It’s rather fitting that Polybush is handmade in the UK, just like Land Rovers used to be, Polybush manufacture, test, refine, test again and then send to market.