Shims, an integral component in equipment and parts design, are widely used across industries. They are powerful tools with lasting effects on many industrial processes. They can even change the outcome of professional races.
Shims at the 2014 IndyCar Race
According to Racer, Team Penske, a racing team that has competed in the IndyCar, Nascar, and Formula One races, saw its member Will Power fall from third place to eleventh on the final lap of the Houston Grand Prix. Power lost his position when his car’s camber shims in his suspension fell out, causing the right-rear tire to move out of control. Out of safety concerns, Power slowed his vehicle, ultimately finishing eleventh in the race.
This was the third case of malfunctioning camber shims during the 2014 IndyCar season. In May, two racers at the Indianapolis Grand Prix had similar issues to Will Power. Part of the reason in Houston was said to be the bumpiness of the track itself, with collisions on these causing shims to fall out and make drivers lose control of their vehicles.
Slotted Camber Shims in Vehicles
A significant reason, however, was the fact that teams were allowed to use slotted camber shims. These are machined washers with a groove cut in them that provides faster camber changes. According to Performance Racing Industry online, “By loosening the nut that retains the threaded suspension upright clevis which fastens the connection to the upright or tire, slotted shims can be easily installed and removed. If the nut holding the clevis to the upright loosens while the vehicle is on the track, or if the clevis is bent enough in an impact or collision, the slotted shims could fall out and cause problems for drivers.”
Previously, Dallara, makers of the chassis in the Chevy racing vehicles, refined the system by implementing a tab-and-pin locking method to secure the shims. Some teams sought permission to create and use their own locking methods. These requests were denied by IndyCar, explaining that Dallara needed to produce uniform updates for the paddock.
Powerful Components in a Variety of Industries
Just as shims are integral to the safety of vehicles on racetracks, they are essential to equipment manufacture and parts design across industries. Shims are used in aerospace, military and defense, medical component, and mining, in addition to a host of other industries. The wide range of materials in which they can be produced—from aluminum to stainless steel to nickel—makes them versatile and fully customizable to a manufacturer’s specifications.
Shims can also be designed in a range of options, from simple to complex. Moreover, shims are more effective when incorporated into the design at the onset, which eliminates the time and cost of retrofitting precision tolerances on interacting components. Shims can align either parallel or angular surfaces of interfacing elements, compensate for accumulated tolerances during assembly, and add longevity to equipment by reducing wear. Shims are an essential part of vehicle design, adding to the safety and security, just as they can be in construction.