Steering and suspension technology
Steering and suspension assemblies are safety critical components and contribute to the effective and economical running of the vehicle. Although the autumn and winter months are associated with steering and suspension damage, the perilous state of the UK’s roads means that component damage is now an all-year-round occurrence.
Recent MOT statistics reflect these facts and reveal that 13% of vehicles fail on steering faults and 13.25% on suspension faults. So bearing this evidence in mind, it is crucial to drive the message that steering and suspension components must be replaced in like-for-like pairs and that products of matching OE quality are used.
Historically suspension arms (wishbones and track control arms) were produced using cumbersome cast material due to its inherent strength; however these were quickly superseded by the more common double skinned pressed steel products due to their high strength and lower cost properties.
The pressed steel wishbones have themselves evolved over time and can be best noted on the MK4 Ford Fiesta. This model was originally launched with a double skinned wishbone fabricated from pressed steel; however, during its production this was superseded by a single skinned steel unit to crucially save on production costs.
The latest suspension arms are made of mainly aluminium construction which has tremendous weight saving characteristics, but also costs as much as 5 times the price of steel. Therefore aluminium wishbones still tend to be fitted to premium sector vehicles and it is highly unlikely that their use will spread to the volume sector because of the cost implications.
Like wishbones, stabiliser links have traditionally been steel, but VMs such as Peugeot flirted with lighter all-plastic designs before settling primarily on the conventional steel types. Hyundai are currently using a hybrid steel and plastic stabiliser link on a vehicle due for release later in 2011. This offers both a weight saving and the longevity/rigidity required, unlike its mainly plastic counterpart.
Replace in pairs
Garages need to educate their customers about the necessity - from a safety, performance and budgetary perspective – of replacing worn or damaged steering and suspension components in like for-like-pairs. This education comes from responsible suppliers like First Line, but needs to be re-enforced by factors who are speaking with garages on a day-to-day basis.
Every good technician knows the difference that a new component can make when paired with a worn component. A good example is when replacing a worn wishbone bush on one axle, but not replacing its counterpart. When the vehicle accelerates or is under heavy braking, the vehicle is highly likely to pull to one side – usually towards the side of the worn bush! This is because the new bush is a lot stiffer and less compliant.
To perform to its optimum efficiency, the modern motor vehicle requires its steering geometry and suspension set-up to be precisely configured and it is only by replacing worn components in pairs that the correct configuration can be maintained. The First Line range of steering and suspension components is one of the most comprehensive in the market and gives factors the greatest possible combination of product availability, matching OE quality and competitive pricing.