Trailing Arm Bushing: Everything You Need to Know
- Trailing arms connect the rear axle of the vehicle to the frame or chassis. They do not only serve as a pivot point, but they also keep the rear axle or rear spindle from moving back and forth while the vehicle is running.
- Like other suspension parts, trailing arms come equipped with bushings, which are typically made of rubber but can also be manufactured using polyurethane or other soft but firm materials. Trailing arm bushings act as pads or cushions that minimize friction between surfaces or between metal parts.
- Although suspension bushings are built to withstand vibrations and shocks, in general, they wear out due to stress and friction, get damaged due to prolonged exposure to heat and petroleum, and dry out due to lack of lubrication.
- Common rear trailing arm bushing symptoms include clunking noise from the rear axle, excessive wear on rear tires, vehicle sway, and uneven vehicle height.
- The price of trailing arm bushing replacements ranges from $10 to $100 per piece, depending on the brand, on the vehicle specifications, and if you are buying per piece or in sets of two or four.
The suspension system maintains tire-road friction, and in doing so, this makes steering more stable and vehicle handling smoother. It also dampens the impact on the road to make the ride less bumpy even as the vehicle drives over dimples and potholes or deals with rougher road conditions.
Faulty suspension components—even something as small as a suspension bushing—will adversely affect driver control. In the process, other suspension parts might wear out faster. If the trailer arm bushing is already chewed up, a complete suspension check must be done to fix the problem at once.
How do trailing arms work in a suspension system?
The suspension system is not the same for all vehicles. It comes in different configurations to match the shape, dimensions, capacity, and overall design of the vehicle. Some use leaf springs, double wishbones, and multi-links. If your vehicle is equipped with coil springs, designed with live axle suspension, or built with independent rear suspension, it probably has what you call the trailing arms.
Trailing arms basically connect the rear axle of the vehicle to the frame or chassis. They do not only serve as a pivot point, but they also keep the rear axle or rear spindle from moving back and forth while the vehicle is running.
What is a trailing arm bushing?
Like other suspension parts, trailing arms come equipped with bushings. Suspension bushings are typically made of rubber. They can also be manufactured using polyurethane or other soft but firm materials. Bushings are found on many parts of the suspension system since they act as pads or cushions that minimize friction between surfaces or between metal parts that form a joint. They keep parts from grinding against one another and from ruining each other due to stress and friction.
Their overall structure and material quality determine how effectively they can buffer shocks and absorb noise from turbulence on the road, especially when the vehicle is driven over rough patches or ground imperfections. Together, suspension bushings help make the handling smoother and the drive safer and better. Some are even designed to support passive rear-wheel steering and other functions.
Why do you have to replace a damaged trailing arm bushing as soon as you can?
Trailing arms, although they are built to withstand heat, friction, and stress, are prone to damage once the bushings weaken, dry out, or get chewed up. Without the much-needed cushion or pads to protect them, the trailing arms eventually deteriorate and break. When this happens, you will have to deal with more than just the clunking noise from underneath and vibrations felt throughout the vehicle.
Steering and handling may suffer as metal joints of the suspension become less protected from stress. This will also lead to a significant difference in suspension performance and quality. If there is any sign of wear on the bushings, trailing arms, and other suspension parts, a complete system checkup is a must to isolate the source of the problem and prevent further damage.
What are common rear trailing arm bushing symptoms?
If you encounter any of these symptoms or conditions, you have to inspect the trailing arm suspension of your vehicle and probably change the old bushings–or even replace them along with the trailing arms depending on what you will find out from the thorough inspection:
If you hear some clunking noise that seems to be coming from the rear axle as you drive over bumps or as the vehicle speeds up, slows down, stops, turns, or backs up, this indicates wear on the rear trailing arms and even the bushings.
If the vehicle seems to sway because of the rear wheels, the problem can be traced to torn bushings or even damaged trailing arms as these allow the rear axle to move freely from the chassis.
Uneven/excessive wear on rear tires
If you notice uneven or excessive wear on your rear tires, there could be a problem with the alignment, caused by a broken trailing arm or a stripped bushing that leads to shifts in suspension.
Uneven vehicle height
If the vehicle seems to sit higher on the other side, one of the things to check are worn bushings and weak trailing arms—these allow rear springs to lift and, in effect, this affects the height of the vehicle.
What causes suspension bushings to break down or wear out?
Although suspension bushings are built to withstand vibrations and shocks, eventually, they wear out due to stress and friction. When the rubber dries out due to lack of lubrication, bushings become hard and inflexible. As they get old, they become less resilient, especially when exposed to heat, fuel, and harsh elements on the road. This also depends on the amount of stress they are put through, such as when driving on gravelly roads or carrying larger loads, or on the environment they are placed in, such as when driving in humid climates or during inclement weather conditions.
What do you have to consider when replacing trailing arm bushings?
A thorough inspection of the vehicle’s suspension system will reveal the underlying cause of the problem since symptoms such as steering issues, clunking noises from underneath the vehicle, bumpier rides, and accelerated tire wear are not isolated to faulty arms and bushings. When bushings make unusual noises, this does not always stem from weakened rubber or material. Bushings dry out because of lack of lubrication. You may have to re-apply grease at some point.
Through complete suspension checkup, you will know if the bushings simply need to be lubricated, cleaned, or changed, or if you will also have to replace the trailing arm or other faulty suspension parts. The repair is best handled by a professional, but if you have the skills, you can carry out the inspection yourself and even do the necessary repair. It is best to use a specially designed trailing arm bushing tool, which allows you to access and remove the bushing without breaking the trailing arm and other surrounding parts. With this tool, you can easily loosen and remove bolts and push out the bushing to lubricate, clean, reassemble, or replace it.
How much do you have to spend on a new trailing arm bushing?
Trailing arm bushing replacement cost ranges from $10 to $70 per piece. Sets of two start at around $20 and may cost as much as $100, depending on the brand and the vehicle specifications. Trailing arm bushing replacements are also available in sets of four, with prices ranging anywhere between $30 and $60. To get the best deal out of your purchase, take time to shop around and compare.
Which Trailing Arm Bushing is Right for Your Ride?
After years in service, has your trailing arm bushing seen better days? If you answer yes, don't waste time; replace it right away. To get the most bang from your buck, consider first some important factors before you pay for a replacement unit.
OE replacement vs. direct fit
Those who want a trailing arm bushing that's as tough as or even tougher than stock can go for an OE-replacement unit. OE replacement bushings are usually manufactured to meet or exceed the criteria set by the crash institute for original bushings. Direct-fit bushings, on the other hand, are ideal for do-it-yourself vehicle owners because they are designed to fit in place of the stock without a need for modification or any complex installation procedure.
Rubber vs. polyurethane bushings
When it comes to automotive bushings, you usually have a choice between two materials-rubber and polyurethane. Each one has its own advantages and disadvantages, but it all boils down to durability versus affordability.
Trailing arm bushings were originally made of rubber, making them more prone to deterioration. More so, the flexibility of rubber works against it and during rough driving conditions, it can affect your ride's handling. However, rubber bushings have the advantage of being more affordable than polyurethane-so much that you can even buy a pair so you'll have a backup.
Like all compounds, polyurethane has the advantage of stability on a molecular level. Since it is much harder and tougher, it doesn't deteriorate or wear out as fast. Between the two, polyurethane is the clear winner-the only downside is that it costs more than rubber bushings.
In the end, it's up to you to balance price with punch-but take our word for it. It's better to spend for a long-term solution than to keep spending on a replacement in the long run just because you want to save a pinch today.
Trailing Arm Bushing Replacement: Step-by-step Instructions
The trailing arm bushing does its job quietly. Drivers don't really pay much attention to this part until it starts to make squeaks or groans. The condition of this bushing is very important for the vehicle's rear axle alignment, so as soon as you notice signs of damage, have it checked right away. If replacement seems necessary, these steps can help you pull the task off without the help of a pro:
Difficulty level: Difficult
Things you'll need:
- Car jack
- Jack stands
- Lug nut remover
- Steel mallet
- Flat washers
- Sheet metal strip
Step 1: Park your vehicle on an even surface, jack up its back end, and support both left and right sides with sturdy jack stands.
Step 2: With a lug nut remover, take off the rear tires and wheels. Carefully pull off and disengage the brake line sensor running to the trailing arms.
Step 3: Loosen and remove the bolts that secure the trailing arm into the vehicle using a ratchet and socket. Put the trailing arm on a table or any work surface and stand directly behind it. The trailing arm must be positioned vertically in front of you so that the bushing will be perpendicular to you within the arm.
Step 4: Push the bushing out by pounding on the inside of the arm using a steel mallet. Force the bushing to the part of the arm that is exposed when the arm is set up in your vehicle. Remove both bushings in the same way.
Step 5: Wrap the metal lip of the trailing arm hole with a thin strip of sheet metal and put a big hose clamp around it to form a ring. Create a funnel that's only like an inch out from the trailing arm.
Step 6: Push the end of the replacement bushing up to the hole and compress it a bit using the hose clamp and the sheet metal ring you made. Grease the bushing and use a long bolt, nut, and big washers to draw it into the hole. The grease will also make it easier for you to slide the bushing into the hole. It may take several tries before you can position the bushing in such a way that it's in the same orientation as the old one the moment it's installed.
Step 7: Once the bushing is in, slot the metal bar in and thump it with a hammer until it slides through to the appropriate depth.
There you have it. Replacing the bushing may be time consuming, but it isn't difficult as it may seem. The bulk of work is actually in removing and reinstalling/replacing the trailing arm. In some cases, you'll need to bleed the rear brakes and adjust the parking brakes. Some bolts also need to be torqued.