While often overshadowed by flashier suspension components like shocks and springs, the control arms and their counterparts, the bushings that connect the arms to the axle or chassis, are some of the most critical components of your build when determining articulation capabilities, highway handling, and necessary maintenance.
First lets understand Bushings or Joints.
Is it a Bushing or Joint?
A Joint is a pivot point usually located at the end of a Control Arm that connects the Control Arm to the axle and/or the frame, allowing for controlled movement and flexibility within the suspension system. It is essential for maintaining the correct alignment and handling characteristics of the vehicle. Joints can also appear on steering systems and sway bar links.
A Bushing is generally located in the joint as the primary functional piece of the Joint.
What Does a Bushing Do?
When a Jeep is navigating through the rocks, the flex is directly enabled by the control arms, which raise and lower the axle as the wheels and tires traverse uneven ground. This action keeps the tires planted, increasing traction and aiding in getting off the trail successfully.
Ultimately, all the Jeep’s contact with the ground is transferred through eight pivotal points – each of the control arm bushings. Four are located up front, and four in the rear, attaching the axles to the chassis. As you can imagine, these bushings are extremely critical components and have a significant influence on how the Jeep handles. Even with top-of-the-line shocks, if the control arm bushings are of poor quality, the Jeep won’t handle well. Similarly, installing taller springs doesn’t guarantee improved articulation; aftermarket control arms and high quality bushings are necessary for the Jeep to perform to its full potential.
The type of bushing chosen also dictates the necessary maintenance. Factory joints and their clevite rubber bushings are relatively maintenance-free but offer limited articulation and are prone to wearing out quickly, necessitating replacement. Some aftermarket joints require frequent rebuilding or lubrication via zerk fittings. If unsure about maintenance procedures, consulting the control arm manufacturer or a qualified mechanic is advisable.
What are the Types of Control Arm Bushings?
So, what’s the best control arm bushings? As with many nuanced decisions, it depends on factors such as daily driving comfort and highway safety versus extreme off-road articulation needs. To facilitate your decision-making process, we’ll discuss some common types of joints and bushings found on Jeeps.
Rubber Clevite Bushings:
Factory Jeep Wrangler control arms and some aftermarket manufacturers opt for solid high-durometer rubber bushings at the connection points between the control arms and the chassis or axle. These bushings are inexpensive and primarily designed for daily drivers with a focus on highway handling. While they reduce some noise, vibration, and harshness (NVH) on the highway, they offer limited articulation, and have a relatively short service life off-road.
Polyurethane Bushings:
Polyurethane bushings, like rubber ones, contribute to dampening between the suspension and the chassis. However, they allow for true rotation rather than distortion. While offering more articulation than factory bushings, they can become squeaky quickly if not constantly lubricated. In addition, the constant micro vibrations wear out the polyurethane bushings causing short life spans and constant maintenance.
Heim Joints:
Heim joints provide extensive articulation and angular movement, suitable for extreme off-road situations. However, their all-metal design transmits significant NVH, making them less ideal for daily drivers. Heim joints require regular inspection and maintenance to prevent premature wear.
Synthetic Elastomer Bushings:
Fairly new to the off roading scene, several companies have added Synthetic Elastomer bushings to their line up. Called Dual Durometer, Giiro, or other trade names, they each have multiple layers of material from a Synthetic Elastomer vulcanized to an outer sleeve with an inner sleeve or sleeves that house a steel tube. Because of the multiple parts and the free moving steel tube, the micro-vibration wear you find in the polyurethane bushings is prevalent here as well. A non sealed surface in some cases allows for dirt and early deterioration of the bushings. Alternatively they do have more flex and NVH than other bushings.
MetalCloak Duroflex Bushing:
The MetalCloak Duroflex Bushing combines the self centering and micro-vibration dampening advantages of OEM-style rubber bushings with the high articulation, rotational value of a polyurethane bushing. Infused with Kevlar, it provides extreme articulation while reducing NVH better than factory bushings. Maintenance free, it allows for high degrees of rotation and misalignment, eliminating binding and maximizing articulation, making it suitable for both on-road handling and off-road capability. No moving parts, it is sealed from dirt and elements that can tear down the surface area prematurely. Simply put, the MetalCloak Duroflex joint lets you have your cake and eat it too.
Final Thoughts
Control arms and their joints play an extremely important role in a well-functioning suspension system. They are the primary driver of articulation and have a significant impact on how your vehicle handles.
Still have more questions about control arms? Or maybe you’re wondering which type of joint will be best for your use? Give our 4x4 experts a call at (916) 631-8071 and they’ll be happy to help you out.
