June 2020 | By: Vera Catalfo

4 Critical Upgrades You Should Look for in a Unitized Aluminum Control Arm

Control arms connect the body of your vehicle to the wheels and act as pivot points in the suspension system. They are the reason why your tires stay on the road when you go over a pothole. Control arms enable the wheels to move up and down independently, while the vehicle frame remains level, for a smooth and even ride.

When control arms become worn, your vehicle may begin to pull to one side and make knocking or squeaking noises. Control arm assemblies typically have two key components, bushings and ball joints. Depending on the type of control arm, you may have the option to replace individual components or you may need to replace the entire unitized assembly. There are three types of control arms on the market.

3 Types of Control Arm Assemblies

  1. Press-In: Use a ball joint which is pressed through a hole in the control arm and friction holds it tightly in place
  2. Bolt-In: The ball joint uses a mounting flange that bolts onto the control arm using bolts and nuts or is riveted in place.
  3. Unitized: which replaces an individual ball joint. They fully integrate the ball joint into the control arm assembly, forming a solid container arm. This design has become very popular in aluminum control arms.

To improve fuel economy and reduce costs, more and more OEMs are using unitized aluminum control arms in their vehicles. Aluminum control arms are lightweight and corrosion-resistant. Since the ball joint is integrated directly into the component, a separate housing for the ball joint is not required, which saves money and reduces the overall weight of the control arm. In an age when Corporate Average Fuel Economy (CAFE) Standards are motivating OEMs to design lighter, more environmentally sensitive vehicles unitized aluminum control arms are a cost-effective solution.

A big downside to most unitized aluminum control arm designs is that they use polymer bearings. They do this because aluminum is a relatively soft metal, and polymer won’t damage it. Polymer bearings, however, are non-serviceable and heat sensitive. When exposed to high temperatures, such as the heat from brake rotors, the polymer begins to soften, causing the bearing to stretch, deform and ultimately disintegrate. There is a way to avoid polymer bearings in unitized aluminum control arms, and there are additional upgrades that make these control arms more durable. Here are four design upgrades to look for.

4 Critical Upgrades to Look For in Unitized Aluminum Control Arms

  1. Bimetallic design: a bimetallic design with a metal ball joint housing and metal bearing threaded into an aluminum control arm creates a stronger, more robust control arm, without damaging the softer aluminum.
  2. Sintered metal bearings: an integrated sintered metal bearing is impervious to heat and provides a more durable, longer-lasting part.
  3. Greasable ball joints: a greasable ball joint enables the flushing out of old grease and contaminants by injecting new grease during inspection and maintenance.
  4. Corrosion Resistant Coating: a control arm coated with a resistant coating and protects against various corrosion factors, including road debris and weather conditions.

Technology is Changing

A pioneer in introducing unitized control arms for all makes and models, Mevotech engineers came up with a stronger alternative to polymer bearings. They found a method of threading the ball joint into the aluminum in a way that allowed them to incorporate a sintered metal bearing in place of the polymer one. This became Mevotech’s patented bimetallic technology.

Mevotech provides the broadest control arm coverage in the aftermarket. Many feature design upgrades to improve durability and extend service life, including thicker, stronger forgings to minimize flexing and twisting, and greasable ball joints to reduce wear. Bimetallic technology allows Mevotech’s aluminum control arms to remain true to the OEM aluminum specification, but improve upon it with metal bearings which are impervious to heat and last up to three times longer than polymer. The result is a high-performance part that provides superior wear characteristics across all driving conditions, and because it is a patented technology, it’s only made by Mevotech.