Your heavy loads put a lot of stress on your torque rods. Understand their vital role in your suspension system.

Ensure Your Heavy-Duty Truck and Trailer Torque Rods Are Operating at Optimal Performance

You expect a lot from your truck. You demand heavy hauls from your trailer. Regardless of what you are driving, your application’s suspension performance is paramount. You know that downtime can cost you big. Your success is why it’s important to perform proper inspection and maintenance of all your suspension components, especially when it comes to your medium and heavy-duty torque rods.

If you are a driving a class 8 truck, you know that if your vehicle is in the shop or service center, you are losing money due to downtime. Knowing how to properly maintain your suspension system to ensure continual efficient performance and dependability, can help prevent this. Not only that but damaged torque rods are one of the most severe CSA violations. So if you don’t want to receive a seven-point penalty, you should read this article.

In this article, we’ll explain the importance of your torque rods, explain how they work, what components make up the torque rods, and how to prevent costly repairs by performing regular maintenance. Some of your top questions we’ll answer are:

  1. What is a torque rod?
  2. What does a torque rod do?
  3. What are the types of torque rods?
  4. What are the main components of a torque rod?
  5. How do you check torque rods?
  6. How do you measure torque rods for replacement?

What is a Torque Rod?

No matter what you call it (radius rod, radius arm, torque arm), the torque rods play a vital role in your truck or trailer’s suspension and tires. Torque rods can be longitudinal (running forward and aft) or transverse (running side to side). 

Common Types of Torque Rods

Transverse Torque Rods – more common on a truck

  • Absorbs lateral and side loads
  • Provides roll resistance
  • Keeps axle centered laterally
  • Controls axle walk-out

Longitudinal Torque Rods – used for both truck and trailer

  • Absorbs accelerating and braking loads
  • Restrain axle housing rotation
  • Controls vehicle driveline angles
  • Provides improved component life

What Does a Torque Rod Do?

Why are torque rods important? Common in medium and heavy-duty trucks and trailers, torque rods are mainly responsible for controlling the wheel movement of your rig. However, that’s not their only function. They resist lengthening and control the twisting of your axles and suspension when in use. When you consider the force that is generated simply by your driving down the road, you can appreciate the stress that these suspension components endure.

Torque rods are responsible for the following:

  • Torque rods control driveline angles.
  • When stopping and accelerating, torque rods restrain the rotation of your axle housing.
  • Torque rods absorb leaning, maintains alignment and forces when you are driving.

What are the Main Components of a Torque Rod?

Torque Rod

Simplistic in design, torque rods only have a few components. It is a rod or a shaft with a bushing on each end. At Wheelco, we recommend using torque rods designed by Atro Engineered System. Atro’s torque rods include rods that you can select to fit your truck or trailers requirements:

  • Fixed length
  • Adjustable length rods
  • Two-piece rods
  • Lateral rods
  • Radius rods
  • V-rod assemblies
  • Small eye rods
  • Custom length rods made to your specification

Torque Rod Bushing Types

How to identify the different bushing types to ensure the correct replacement for your torque rod.

The three main bushing types used in torque rods are as follows:

Depending on your application’s need, you may have various bushing types on each end.

How Do You Check Your Torque Rod?

Since torque rods are responsible for controlling the twisting movement in your driveline, if they become worn or damaged, severe issues can arise with your suspension. If not properly replaced, major damage may occur to your suspension system and/or driveline components.

Inspect your torque rod immediately if you experience any of these common signs and/or symptoms: 

  • Excessive or unusual tire wear, feathering or odd tread patterns
  • Wandering
  • Thumping sound when accelerating
  • Back slap
  • Driveline whip or driveline component failures
  • Axle hop
  • Dog Tracking in trailers
  • Pull in trucks
  • Loss of ride height
  • Axel housing fatigue
  • Ring and pinion failure
  • Suspension misalignment
  • Clunking sound while braking
  • Premature wear on your beam bushing
  • Air spring failure
  • Differential seal failure 

Since torque rods are susceptible to wear and damage, like most suspension components, you should check them on a regular basis. Check your torque rods according to your specific application preventative maintenance. However, how do you know when they need to be repaired or replaced when inspecting them? 

Wheelco Quick Tip: Visually inspect torque rods and bushings every six months or 50,000 miles, whichever comes first.

Here are some general guidelines but be sure to consult with your application’s specific recommendations.

  • Torque rod is bent
  • Movement greater than 1/8″ at the end of the rod
  • Center pins are worn or misaligned
  • Cracked bushings
  • Expanded mounting pin bolt hole

Wheelco Recommendation: If you can move the end of your torque rod easily with your hand, it’s most likely time to replace it.

How Do You Measure Torque Rods for Replacement?

Need to replace your torque rod? Choose your torque rod style first.

You’ll need to consider the shaft diameter, width, and outer bushing diameter as well as the bushing angles, unless you are using an Atro style torque arm.

How-To Steps to Measure Your Torque Rod in 4 simple steps

  1. Measure center to center of your bushings
  2. Identify bushing type for each end
  3. Check mounting angels and how they are aligned to the torque rod shaft unless you are using Atro torque rods because they feature free-rotation bushings.
  4. Measure the shaft diameter

Wheelco Quick Tip: Measuring the center-to-center of your bushing is vital when realigning your suspension.

Recommended Torque Rods 

At Wheelco, we recommend using Atro’s torque rods when you are looking to replace your suspension system components. We trust Atro in our medium and heavy-duty trucks and trailers.

What’s different about Atro’s torque rods?

Atro truck and trailer torque rods combine innovative engineering and physically superior polyurethane bushings. Atro’s rods are engineered and constructed to meet or exceed OEM standards.

Features and Benefits

The combination of polyurethane material, mechanical welding, and forged eye components creates a better torque rod. Most rods feature free-rotation bushings – an outer metal sleeve with a rotating inner sleeve/pin. This free-rotation design with Atro’s specially designed polyurethane eliminates the windup and walkout rubber bushings experience, last longer than OEM bushings, put less stress on other suspension components, and simply keep your trucks out of the shop and on the road.

Easy Installation

This design makes rod installation easy as they automatically zero out to ride height and eliminate the clocking positions. Atro’s proprietary polyurethane bushings are chemically resistant to contaminants such as road salt, grease, oil, acidic cleaning solvents, hydraulic fluid, and diesel fuel and feature significantly higher tensile strength and tear resistance than OEM rubber or other polyurethane bushings.

Also when installing “bushings only” in an existing torque rod ,the free-rotation bushings make it extremely easy not having to press them in with the exact pin clocking, for they simply can be turned to line up the bolts during installation.

No Maintenance

Atro bushings require no maintenance or grease and you get torque rods and bushings that outperform and outlast OE or other replacement rods and bushings, resulting in less downtime and lower cost-per-mile.

Need to replace your torque rod? We offer a full line of OEM, 2-piece, and custom quality heavy-duty torque arms for all types of trucks and trailers. How about help identifying the correct type of torque rod? Our experts are ready to help you get exactly what you need. Want assistance installing them? No problem. Our service technicians have years of experience installing truck and trailer suspension components. Have more questions? We can help! Simply give us a call or stop by one of our stores today.