This month Peter muses parts terminology and classic car parts availability.
Last month, Martyn the Editor and I exchanged several of what my other half Sarah described as “very boring emails.” The topic of this alleged tedium was the correct term to describe the Kia Sorento front suspension components, the renewal of which we featured last month under the eventually-agreed title of ‘Front Control Arm’ swap…
The issue Martyn identified was that in my original copy, I called the parts in question ‘Lower Wishbones’. I used that term because the parts in question have one mounting point at the wheel end, but two where they attach to the chassis. Hence three mounting points which to my mind made it a wishbone; an arm, surely, should have just two?
However, according to the febi bilstein parts listing, the component in question is called a “Control Arm with bushes and joint.” And to add further confusion, we’ve also heard the component in question referred to as a “lower arm.”
So, which is correct? And does it matter? To answer the second part first I think it does. With the ever-increased complexity of modern cars and increased reliance on automated parts-ordering systems, using a term that the system doesn’t recognise can lead to either no stock showing when there is stock or, if ‘the system’ tries to guess what is meant in an Artificial Intelligence kind of way, the wrong item arriving. One of the first things a human parts assistant learns is the unofficial names people use for different bits, and how they translate into parts listing terminology.
Where different names are used there is usually a historic reason. With front suspension components, our story starts in the 1950s, when manufacturers began replacing solid beam axles running on leaf springs with independent front suspension. Leaving aside torsion bars for a second, this was generally done in one of two ways. Most British manufacturers used twin-wishbone type arrangements, with a coil spring sandwiched between a lower wishbone-shaped component and a solid part of the car’s structure. There was also a top link; sometimes, this would take the form of a lever-arm shock absorber, otherwise there would be a separate upper wishbone type component and a telescopic shocker inside the coil spring.
Ford, however, had designed a different system. The Macpherson Strut features a single suspension upright which incorporates a coil spring and shock absorber, and attaches at the top to a specially reinforced section of inner wing. At the bottom, because the suspension functions are all contained within the strut, all that’s needed is a lower arm to hold the bottom of the strut in the correct position in relation to the car’s body structure and allow for suspension up and down movement. As this had just two mounting points (one at each end) and its job could be described as
