Being a fleet engineer or procurement manager comes with a lot of responsibility. Often, you’re tasked with balancing lifecycle cost with quality, looking for longevity of parts, and minimising downtime when it comes to vehicles in your fleet.
As such, you must ask the right questions of your suppliers, regardless of the size or importance of the part. We all know that just one minor issue can cause a vehicle to need repair, which can have a costly impact when it’s a fleet of vehicles that need to be taken off the road.
In order to help you make some better-informed decisions, we’ve compiled a list of what to ask your spring supplier to make sure you’re not facing bigger costs over the long term.
What’s Going Wrong in Spring Selection?
When it comes to choosing a reliable spring manufacturer for your fleet, you want to ensure the quality can meet the demands of your vehicles.
All too often, we see fleet managers baffled by premature spring failure of the suspension. At Airedale Springs, we find that there are typically three main causes of why springs fail sooner than expected.
Why Your Suspension Springs May Fail Prematurely
Inadequate Fatigue Resistance
Suspension springs are expected to last thousands (if not millions) of cycles. Every bump in the road causes your springs to absorb the shock of different road surfaces, making for a smoother journey. Fatigue resistance refers to the number of cycles a spring can withstand before it needs to be replaced.
If your supplier has not accounted for the weight of your vehicle and its load correctly, or is using insufficient materials that aren’t strong enough, your spring could prematurely weaken and crack. A broken suspension spring is a serious issue that can cause unnecessary downtime if not properly addressed as part of your regular maintenance.
Testing in a lab – not the real world
If your supplier isn’t fully accounting for your vehicle’s use and the weight of the load, it could lead to premature suspension spring failure. As such, it’s essential that the testing phase accounts for road conditions, humidity, journey distances, and the weight of goods that your fleet will carry on a daily basis.
A spring that passes standard tests may, therefore, fail in real life.
Rather than using your own vehicles as the guinea pigs for testing, there are, in fact, computer programmes that account for all of these different factors as part of the spring design phase. The size, style, and material of your spring can be adjusted based on your company’s use so that you can avoid your suspension springs failing prematurely.
Poor Corrosion Protection
Underbody exposure to elements such as humidity, surface water on the roads, and road salt all lead to the metals in springs corroding, shortening their service life. That’s why it’s imperative to choose the right material for your spring in the first instance and then explore further corrosion protection (such as powder coating) to create longevity.
Three Essential Questions to Ask Your Spring Supplier
Now that you’re aware of what can cause the springs in your vehicle fleet to fail prematurely, it’s important to ask relevant questions about them at the beginning of the process.
After all, by investing in a higher quality of material and protecting a spring’s integrity from the outset, you’re avoiding unexpected downtime as much as possible.
What grade of material is used, and is it suitable for dynamic fatigue resistance over the vehicle’s lifecycle?
Your supplier should be able to advise on a spring material with a very high fatigue resistance limit, ensuring it can endure repeated stresses throughout the lifespan of your vehicle. By doing so, you’re lowering the lifecycle cost of your vehicle.
Using a lower-grade of steel may seem more cost-effective in the short term, but the cost of replacing more frequently soon adds up. As the saying goes, “Buy cheap, buy twice” or even three or four times when it comes to a spring that is being stressed hundreds or thousands of times each day.
What fatigue testing or lifecycle simulation processes are performed to validate durability?
You want to ensure that your spring is fit-for-purpose and hasn’t merely passed standard testing. By ensuring that road conditions have been taken into account, you’re better equipped to ensure that your springs last within the expected timeframe rather than breaking prematurely.
A lifecycle simulation process can be carried out with Computer Aided Design (CAD) programmes. This style of software enables the designer to adjust the spring based on vehicle type, load size, distance travelled, etc to measure how long the spring will last without having to use trial-and-error methods.
What protective coating or finish is applied to prevent corrosion and extend service life?
Roads are notorious for creating conditions that cause metals to corrode. They have surface water, debris, and road salt to name but a few ways that your underbody materials can begin to corrode.
Without adequate corrosion protection, the metal weakens, causing it to rust, which can make the spring fragile and prone to breakage prematurely. If a vehicle spring breaks, it can have dangerous consequences, meaning it needs to be taken out of service immediately, which can result in additional costs due to potential downtime.
Although stainless steel is already highly resistant to corrosion, adding a protective coating can further prevent your spring from corroding over an even longer period.
There are several options for protective coatings for springs, depending on their application and the type of metal used. Some examples include:
- Spring plating – this is where a thin layer of metal, such as zinc, nickel, or chrome, are plated onto the surface of the spring.
- Powder coating – this involves applying a dry powder coating onto the surface of the spring before curing it with heat to create a hard, protective layer.
- E-coating – used for complex-shaped springs, e-coating provides a uniform and corrosion-resistant finish
- Anodising – typically used for aerospace and military applications, this protective coating is created by immersing the spring in an electrolyte solution and applying an electric current to create a hard oxide layer.
How Airedale Springs Supports Fleet Engineering Teams
By working closely with fleet engineers, Airedale Springs can accurately determine the best design of spring and materials used based on your unique application. Heavy goods vehicles are inevitably going to need a different spring to those used in a fleet of taxis, and so we create bespoke designs tailored to your business and use.
Not only do we offer a design process tailored to your individual needs, but we also stress-test them in-house using our state-of-the-art computer programmes to ensure they match the specific conditions of your business. We also offer a variety of corrosion-resistant materials to prevent premature suspension spring failure.
For technical advice or a tailored spring solution, get in touch with Airedale Springs by calling us on 01535 643456.