Have you ever seen the term UCA in forums or videos, or heard it from friends? If they are car modification enthusiasts, they are almost certainly talking about upper control arms. This is the first concept we want to introduce to you. Enjoy high quality control arms with free shipping at KSP Performance. Because automotive terms are as complex as their meanings, we will use UCA instead of upper control arms in the following.
The UCA is at the heart of the front suspension system. In other words, the control arm is the link between the front wheels and the car. Upper control arms and lower control arms are all control arms. It is attached to the wheel assembly at one end and to the body frame at the other. UCAs help the driver control the vehicle. They also guide the wheels up and down while driving. In conclusion, UCAs play a vital role in the overall stability and driving performance of the vehicle despite their simple appearance.
Where is UCA?
To explain this question, we need to start with the car suspension system. The suspension system is the assembly of all the components that connect the body to the wheels. They are responsible for transmitting power, controlling steering, and absorbing shocks.
There are different types of suspension systems depending on their structure. Double‑wishbone suspension is one of the most common front suspension systems on modern cars. The UCA we are talking about is an important part of this system.
As shown in the diagram, there are two wishbone‑shaped control arms, upper and lower, connected to the knuckle. This structure is called a double‑wishbone suspension, also known as double A‑arms.
Nowadays, most high‑end sports cars and racing cars use front and rear double‑wishbone suspension. Premium sedans usually use a front double‑wishbone suspension and a rear multi‑link suspension. High‑end SUVs and pickup trucks typically use a front double‑wishbone suspension and a rear coil‑spring solid axle suspension.
Why do we need to replace the UCA?
By now, you should have a clear understanding of the role it plays in a double‑wishbone suspension. You may also have heard a lot of discussion about UCA replacement. It is a topic that is widely discussed among off‑road enthusiasts.
Of course, there is no denying the improvement a better UCA can bring to the performance and driving experience of a vehicle. But before discussing that, it is important to understand what you really need.
Wear of the ball joints and bushings
Usually, the ball joint that connects the UCA to the knuckle is the key source of the problem, and you do not need to replace the UCA in the early stages.
For example, a Toyota once had a steering wheel that shook violently at high speeds, but the issue was completely fixed after the ball joints on both UCAs were replaced.
Likewise, worn bushings can make it impossible to accurately position the wheels (failed wheel alignment), which can cause tire vibration and rattling and even accelerate tire wear.
Can the OE UCA withstand intense off-road driving?
Many OE arms are made from stamped sheet metal. This manufacturing process allows OE manufacturers to produce UCAs in large quantities quickly and at low cost. However, OE UCAs made from stamped steel may deform during intense use or even break under a single violent impact. Hopefully you will never encounter this situation.
Aftermarket UCAs are produced in smaller batches, and the materials used are usually more expensive. The KSP UCA is an upgraded version of the OE UCA, with greater resistance to impact and deformation.
If you are pursuing better off‑road performance, upgrading to a high‑strength UCA is a good choice. It provides a more suitable range of motion for the ball joints. This improves road feedback, although it may slightly reduce ride comfort.
The KSP UCA for 0–2" lift is designed to directly replace the stock arm. It provides a more appropriate amount of swing for the ball joints and gives your vehicle more support. This helps the front wheels respond better when they encounter road impacts. We use thicker and safer tubing, precisely machined with CNC technology.
Use of new materials
To reduce production costs, manufacturers often try to reduce the weight of components. Some brands have begun replacing metal UCAs with composite ones. We do not know whether you like composites, but we definitely prefer a solid metal UCA.
Must the UCA be replaced after the vehicle is lifted to a certain height?
You may have heard a lot of recommendations about replacing the UCA on a lifted vehicle. In fact, whether you need to replace the UCA depends on your lifting method and lifting height.
Generally speaking, if you have lifted your truck with a leveling kit and the lift height is more than 2", then you will need to change the UCA. Otherwise, any bumps and turns will put considerable stress on the ball joints at extreme angles. Excessive wear can easily put you in danger.
