Common Trailing Arm Failures: Signs, Symptoms & More!
These control arms connect the steering knuckle or wheel flange to the frame through a bushing. The end of the control arm that is attached to the frame must pivot to allow the steering shaft or knuckle to move up and down. Keep reading and discover in this post everything about common trailing arm failures.
The suspension arms are mounted to the vehicle frame via bushings and extend to the axle housing or to a wheel knuckle. The trailing arms run parallel to the centerline of the vehicle chassis and support a drive or non-drive axle against front-to-rear movement .
What is the suspension arm or trailing arm?
Trailing arms are also called suspension control arms, when in reality they are a unique type of suspension system component. Trailing arms are essential for both the stability and ride comfort of the vehicle.
Although regular maintenance and inspection extend their useful life, trailing arms, especially their bushings, are still susceptible to damage. Find out the causes of bad trailing arm symptoms, as well as damaged trailing arm bushings in the next section.
Common Trailing Arm Symptoms and Failures
Problems with suspension system components can lead to an unstable ride and sometimes even control and steering issues. That’s why it’s important to keep track of these parts , including the trailing arms.
Unless it was damaged in a collision, the trailing arm itself does not require special attention. Trailing arm bushings, by contrast, are a different story.
Bushings help reduce friction between two surfaces rubbing against each other, so they are constantly under stress. This makes them even more susceptible to damage. Bushings connect the trailing arm to the frame and axle housing or tie rod end, so bad trailing arm bushings can cause surrounding components to fail.
Checking the condition of the trailing arm and trailing arm bushings can help you avoid awkward and even dangerous situations.
Listed below are some of the common trailing arm failures that you should be familiar with:
1- Knocking of the rear axle
Bad trailing arm bushings can produce an unusual thumping noise , especially when the vehicle is started or in reverse. You may also notice these sounds when the vehicle hits bumps, accelerates, turns, or brakes. If the bushings are not replaced as soon as possible, the trailing arm itself can eventually be damaged.
2- The vehicle is unstable and does not stay in a straight line
Damage to the trailing arm or its bushings can cause the vehicle’s rear axle to move independently of the car’s chassis. This means that the rear of the vehicle can rock to the side, especially when turning or hitting a bump in the road.
Also, if the driver attempts to drive in a straight line, the rear wheels may completely change the direction of the vehicle.
3- Excessive and uneven wear of the rear tires
If the rear axle drifts out of its proper position due to a bad trailing arm or bushing, the vehicle may have to drag the rear tires while moving , or the front tires may have to change direction. This changes the direction the rear axle is pointing and can cause tires to wear on their new leading edge.
4- The vehicle is lower on one side
This is a common failure of the trailing arm. When the arm bushings are worn, they allow the rear springs to lift that side of the vehicle slightly higher. This causes the height of the rear of the vehicle to go up to approximately one inch.
What Causes Trailing Arm Failure
As mentioned above, the trailing or trailing arm itself rarely fails, except when damaged by a collision. Absorbing noise, minor vibrations and shock, trailing arm bushings are more susceptible to damage due to a number of factors.
1- Extreme heat
Due to their location, trailing arm bushings are regularly exposed to extreme temperatures . High heat, in particular, can cause the rubber cushioning material in bushings to crack and harden.
2- Excessive torque
Torque can also shorten the life of the bushings. If the bushings allow excessive rocking of your vehicle, they can twist and eventually break. This is particularly dangerous because the steering may not be as responsive and the driver may lose control of the vehicle completely.
3- Liquid leaks
Lastly, fluid leaks can also cause bushings to deteriorate and potentially fail.
When to change the trailing or trailing arm?
Driving with damaged, bent, or cracked trailing arms is not safe or prudent, as it can cause the rear axle(s) to separate. This can cause further damage to surrounding components , so you should treat trailing arm problems as soon as you spot the signs.
Depending on your situation, you may consider purchasing a completely new unit instead of just replacing the bushings. Replacing the entire trailing arm may be the most cost effective option as bushing replacement often requires a heavy duty hydraulic press and/or torch and this may not be within the reach of the average DIYer.
Please note that changing the ride height of your vehicle affects the angular position of the trailing arms, which can cause instability. If you are planning to install a new lift kit on your vehicle, you should also pay close attention to your trailing arms and replace or adjust them as necessary.
Vehicle-specific repair manuals and databases can help you locate and repair faulty trailing arms and/or bushings . They are the perfect references because they contain detailed repair information, illustrations, and easy-to-understand diagrams.
However, if you are new to vehicle repair, you can always ask a certified mechanic or technician to do the work for you.
How much does a replacement suspension arm cost?
A replacement trailing arm can cost anywhere from $17 to $430. Prices are often affected by a variety of factors. Rocker arm replacements are typically sold individually or in sets of two or four . Kits are also available that may include hardware and other components.
