#Control arm full
#Control arm crack

#Control arm crack

Being cast aluminum, they don't corrode quite like the steel control arms do, but since aluminum is a softer metal, they do bend and crack when things go wrong. Over the years, many control arms have evolved from their humble stamped steel beginnings to elaborate cast aluminum pieces that are stronger and lighter than ever before. If you drive a truck with independent front suspension, take a peek under the front of it. They are extremely strong and can withstand harsh environments better than the stamped steel control arms. When used in front suspensions, they are often wishbone shaped, with bushings on the inside and a ball joint on the outside. Luckily, these control arms are usually the most inexpensive to replace.Ĭast Iron control arms are very popular on modern vehicles, especially trucks and SUVs. Once the rust takes over, replacing the bushings and ball joints becomes quite a challenge, and sometimes impossible without damaging the control arm. When stamped steel control arms live in a wet environment, they are nearly guaranteed to deteriorate from rust.

#Control arm full

This style of control arm often held coil springs in place on full framed cars, and was also an attachment point for shocks and sway bars. The oldest versions of control arms were most commonly made from stamped steel because it was cheap, fast, and easy. Some vehicles don't come with adjustable camber ability from the factory, so when a car like this arrives at an alignment shop and needs the camber corrected, panic can sometimes ensue.

To set the camber properly with adjustable upper control arms, the vehicle needs to get an alignment by somebody that really understands what is going on. If not corrected, the tires won't have the proper traction, and they will wear unevenly and prematurely. When a lowering kit or a lift kit is installed on a car or truck, adjustable control arms are often needed to correct the negative or positive camber that goes along with them. Adjusting camber is a huge factor when it comes to racing, stance, and the lowering or lifting a vehicle. Positive camber means that top of the wheel is tipped outward, away from the center of the vehicle. Negative camber means that the top of the wheel is tipped inward toward the center of the vehicle. Camber is the vertical alignment of the wheels. When a vehicle has independent rear suspension, it may have upper and lower A-Arms, trailing arms, or some other unique design that fits the shape of the vehicle.Īdjustable control arms are used to adjust wheel camber. These control arms are called 'trailing arms' or 'rear trailing arms'. Most often, it is three or four control arms with rubber bushings on each end. This also means one less ball joint, and a couple less rubber control arm bushings to worry about.įor the rear of a vehicle with a solid axle, any style of control arms might be used to connect the rear axle to the frame or unibody. An upper control arm isn't needed because the strut takes its place. When a vehicle has a MacPherson strut style front or rear suspension, lower control arms are the only type used. This design is still common on many modern vehicles because it just plain works.

They were also called 'A-Frames' or 'A-Arms' depending on who you talked to (wishbones look like the letter 'A' by the way, if you aren't familiar with poultry). As you can imagine based on the name alone, the upper and lower control arms looked like wishbones. Long ago, 'double wishbone' suspension was the norm on the front of most cars. Let's go back and start with the basics.Ĭontrol arm design changes as fast as automotive design and manufacturing technology does. That being said, it's often an arduous task. Most ball joints and bushings are removable from the control arms with the help of a press, and are able to be replaced as needed. These allow the control arm to rotate up and down without binding up. The vast majority of control arms will have a rubber bushing or ball joint mounted securely to them. Now, you can't talk about control arms without talking about ball joints and rubber control arm bushings. Over this time, they have come in a variety of shapes, sizes, and materials, but they have always served the same exact function-to hold everything together! They have been an integral part of suspension systems for nearly a century. In the most basic of terms, the control arms allow up and down movement of the suspension while holding the knuckles, spindles, and axles firmly onto the car. Control arms are one of the most boring yet mechanically impressive parts on a car.