Suspension components have evolved significantly since the introduction of the leaf spring several decades ago. Today's modern suspension is engineered to withstand wear and tear that cars, trucks, and SUVs dish up on a daily basis. At the root of the suspension on most vehicles is the trailing arm, which aligns the pivot point of a body with the suspension by way of utilizing a series of arms and bushings for support. Under many circumstances, the trailing arm bushings can withstand tremendous abuse and last for a very long time. However, they can be damaged for multiple reasons and when they become damaged or worn out, will display a few common symptoms that will alert the driver that it's time to have them replaced.
What is a trailing arm bushing?
The trailing arm bushings join the axle and pivot point on the body of the vehicle. They are part of a trailing arm suspension in your vehicle. The front trailing arm consists of a set of bushings attached to a bolt that runs through these bushings to hold the trailing arm to the chassis of the vehicle. The purpose of the trailing arm bushings is to cushion the movement of the suspension while holding the wheel on the correct axis.
The bushings absorb minor vibrations, shocks, and noise from the road to make for a smoother drive. The trailing arm bushings do not require much maintenance, but can wear out due to excessive use, driving on bumpy roads frequently or due to the elements the vehicle drives in frequently. There are a few common causes of worn out trailing arm bushings that include:
- If your bushings are made of rubber, high heat may cause them to crack and harden over time.
- If bushings allow excessive roll on your vehicle, this can cause them to twist and ultimately tear. This can cause the vehicle’s steering to not be as responsive and cause you to potentially lose control of the vehicle.
- Another problem with trailing arm bushings is if transmission coolant or petroleum leak on the bushings. Both of these will cause the bushings to go bad and potentially fail.
It is common for the trailing arm bushings to wear out on many vehicles navigating the roads we drive daily because of the reasons listed above as well as a few more. When they wear, the trailing arm bushings will display a few symptoms and warning signs that will indicate that they should be replaced by a professional mechanic. Noted below are a few of these common warning signs and symptoms to be aware.
1. Clunking noise when you accelerate or brake
A bushing’s job is to provide cushion and a pivot point for metallic arms and supporting joints. When the bushings wear out, metal tends to "clank" against other metallic components; which can cause a "clunking" sound to appear from under the vehicle. This sound is typically noticed when you drive over speed bumps, or driving onto a driveway. Clunking sounds can also be an indicator of other bushings in the front suspension system such as the steering system, u-joints, or stabilizer bar. Due to this fact, it's a good idea to have a professional mechanic inspect your vehicle if you hear this type of sound, before you have it repaired.
2. Excessive wear on tires
The trailing arm is part of the vehicle's suspension system. When these components wear out or become damaged, the suspension becomes misaligned, which can cause the tires to shift its allocation of weight to the inside or outside edges. If this occurs, the tire will create more heat on the inside or outside edge of the tires because of the misaligned suspension. Worn out trailing arm bushings are known to cause the suspension to be out of alignment and lead to premature tire wear on the inner or outer edge.
If you visit a tire shop or have your oil changed and the mechanic tells you that the tires are wearing more on the inside or outside of the tire, on either side or both sides of the vehicle, have a professional mechanic inspect your vehicle for an issue with the trailing arm bushings. When the bushings are replaced, you'll have to have the suspension adjusted again to be aligned properly.
3. Steering is loose when turning corners
The steering and suspension system work in conjunction to allocate distribution of weight for the body and chassis of the vehicle as it turns. However, when the bushings of the trailing arm are worn out, the weight shift is impacted; sometimes delayed. This can cause the steering to feel loose when you turn to the left of right, especially during slow, wide-angle turns (like driving into a parking lot or when you make a 90 degree turn).
The trailing arm bushings are critical parts of your vehicle’s suspension. If you notice any of the above symptoms, contact a local ASE certified mechanic so they can inspect and replace the trailing arm bushings if needed.