We are rarely bothered about the minor parts of our lives. Our cars are filled with such small parts that we really couldn’t care less about. However, the harmonious coordination between these components is what keeps a vehicle functional. One of them is the lower control arm bushing, also known as a control arm bushing.
This part is fitted onto the frame side of the vehicle’s control arm. The location of the bushing might vary depending on suspension types; we will get to that later.
In this article, we discuss worn control arm bushing signs, function, location, and replacement cost in case the bushings have to be changed.
- Common Causes
- Bushing Repair
- Replacing Control Arm Bushings
- Replacement Cost
- Aftermarket Vs. OEM parts
The Function Of The Lower Control Arm Bushing
The control arm bushing acts as a bridge between the vehicle frame and its suspension. There are 2 kinds of control arms: the lower control arm and the upper control arm. The lower control arm comes with a side-mounted rubber bushing that covers the metal parts constituting the connection. In addition, the rubber absorbs a vehicle’s vibrations from minor jolts and shocks.
The rubber’s effect is better than that of springs, thanks to its location. If the rubber bushing contains grease inside it will lubricate the part to decrease friction. A central rod connects the metal sleeve protruding from the suspension’s interior to the vehicle frame. The outer sleeve is linked to the wheels on two ends so the sleeves can move freely.
This is why the control arm and control arm bushing face a lot of stress during the rotation and movement of a vehicle. Over time, these bushings get harder and begin cracking – a situation that can cause an array of problems.
Control Arm Bushing Location
The control arm can be found on the control arm that is bolted to the frame side of the vehicle. A control arm is located at the end of the suspension – close to the front suspension. You can also find rear lower control arm bushing in the rear suspension of a 4WD, based on the kind of suspension.
Lower Control Arm Bushing Symptoms
The most common lower control arm bushing symptom is losing vehicle stability at higher speeds. Chances are, you will also notice indications of trembling speed or uneven tire wear. In some cases, a vibrating steering wheel may join the parade as well!
Numerous signs will tell you that your car’s control arm bushing is not functioning properly. You might notice a change in steering and comfort, but other problems may accompany the case depending on the seriousness of the situation.
1. Vehicle Stability Has Dipped
If a lower control arm bushing goes bad, you will feel a reduction in driving stability. As we mentioned already, the control arm bushing provides stability to a car. While you are driving, the vehicle moves over many things, from small stones to debris. The car will not vibrate if it rolls over the debris.
If the lower control arm bushings go bad, you might hear rattling sounds while driving, particularly when you move the car around. Nobody wants such an unpleasant driving experience.
2. Uneven Tire Wear
Since the lower control arm bushing keeps the 2 metal sleeves tight and nice, the sleeves move and vibrate when the vehicle moves. As this component is connected to the wheels through an outer sleeve, the control arm’s movement can stop the wheels so they do not contract the road as much, which leads to irregular tire wear (front tires).
3. Steering Trembles
If you accelerate from a dead stop, the steering might be wobbly and the front of the vehicle starts to jitter and shake when you rotate the vehicle or trigger the brakes. This happens because the control arm bushing experiences excessive play and does not secure the wheel in position properly.
4. Reduced Braking Performance
Despite the control arm bushings having no straight link to the brake system, the component does impact vehicle braking. If the lower control arm bushings go bad, the braking might not be affected greatly, but it could get unstable. Thus, the front end of the vehicle bounces abnormally due to the generated inertia when the vehicle stops.
Left unattended, this can create more issues in the future. The excessive vibrations might make other parts of the car come loose or worse: break off.
5. Steering Wheel Vibrates
Connected to the steering system, the wheels are joined to the suspension through the control arms, therefore making a direct link between these parts and the steering wheel. If the steering wheel stands vibrating when braking or turning, bad control arm bushings may be the culprit, since they do not dampen the minor vibrations that happen when steering and turning while driving.
Common Causes Of Lower Control Arm Bushing Noise
Weird clunking sounds coming from your car are never a good sign. Although there might be numerous reasons behind this unnatural behavior of your vehicle, an issue with the lower control arm bushing will exacerbate the situation, thus, increasing the noise. If you pay attention, you will find this noise quite similar to what you hear when someone knocks on your door.
There are five of the most common reasons behind a malfunctioning lower control arm bushing.
1. Worn Control Arm Bushing
Much like most parts of a car, bushings will not last forever. Over time and use, the bushings sustain wear and tear. You will start to hear a subtle clunking noise when the bushings are just starting to deteriorate, but the sounds get more consistent and louder with additional wear.
2. Loose Bushing
A loose lower control arm bushing will get knocked around within the metal parts surrounding it. This may not always mean that the bushings are bad. Maybe you drove over a large bump that knocked it out of place. Alternatively, a mechanic might have loosened it by mistake while working on related areas of the vehicle.
Whatever the case, loose bushings generate the same obnoxious knocking noises.
3. Broken Bushing
Lower control arm bushings may break from excessive wear and tear. We mentioned before how this part may sustain damage from a past repair session conducted by a mechanic. A broken component will result in loud clunking sounds. However, it will not get louder progressively like with worn bushing.
4. Driving On Uneven Terrain
When you drive over irregular terrains, like a rocky or gravel road, the clunking or knocking sounds will get significantly amplified. On the other hand, a bushing in better condition would not loosen up or rattle around when you drive over this sort of terrain. However, if the bushing is not in place, the turbulent motion of the car as its driven could further loosen up the bushings.
5. Hard Acceleration
If the bushings of your vehicle are loose, the knocking sound will be the loudest when you are starting from a standstill. Imagine your vehicle is parked in a garage, and you change the gear to “Drive” and press the gas pedal. At this point, the knocking will be the strongest.
How A Mechanic Inspects A Lower Control Arm Bushing
Like many other suspension parts, the control arms cannot be checked properly at a drive-thru fast-lube location. You can only inspect the lower control arm bushing by lifting the vehicle on a hoist. Car owners should be picky with their choice of go-to mechanic as an actual professional will make all the difference. They will make sure to check all parts of your vehicle regularly to keep away damages from potential component decay.
If you suspect something is wrong with your vehicle’s suspension system, try to get it checked immediately. Some auto shops offer free inspection if you allow them to fix any confirmed problems later on.
Do you have some level of auto-repair expertise? You can put that to good use and repair the bushing yourself. This repair is not generally that expensive but if you still want to save a few coins, check out this step-by-step guide.
To start, you must remove the wheels of your vehicle and jack it up on the support of jack stands. Also, make sure to wear gloves and protective eyewear before doing anything to your automobile.
Step 1: Ball Joint Releasing
Start by releasing the joint. For that, you will need a big wrench (20mm – 24mm) or socket. Loosen the ball joint nut once the cotter pin is removed. Use a hammer to strike the control arm.
If you are doing the job on a suspension, use a hydraulic jack to hold the arm and then slowly lower it when the ball joint is freed.
Step 2: Taking The Sway Bar Link Out
A sway bar link will connect the control arm to the sway bar. Take off the nut with a 14mm or 15mm socket or wrench. There might be a mini taper fit at this joint which you will have to shock loose using a ball joint. Hold the sway bar link and take it away from the mount. By doing this you are moving the sway bar link out of the way.
Step 3: Take Off The Bolts
Two control arm mounting bolts will be holding the fixture in position; they could be vertical or horizontal. Use a 19mm – 22mm socket or wrench to free and remove the bolts. A few bolts will contain a nut on the rear which will have to be secured by an extra wrench. As these bolts will be rigid, make sure the wrench or socket is safely placed on the bolt’s head to prevent rounding.
You can use a universal socket and joint to extract the rear control arm bolt. Once the bolts have been removed, keep your hands on the arm as they might be loose.
Step 4: Removing The Arm
In case the control arm remains on its mounts, grip the component with a steady hand and pull it outward. Move it up and down to slowly release it from the frame mounts.
Step 5: Replace The Bushings
If you are only changing the bushings then follow up on this step. If you plan on changing the whole control arm, read up to step 6 of this guide. Find a match for the old bushings. Make sure the match is identical. Press to remove the worn-out control arm bushings and install a new one.
Start by marking the orientation to confirm the correct placement of the new bushing. If the bushing is installed incorrectly, it will tear during movement. Observe the part so its flex part is in the same location as the former.
Place the lower control arm in a hydraulic press and with a pressed cup and cone, force the lower control arm bushing away from the arm. You should be able to hear a “pop” sound when the bushing begins to move.
Keep pressing the control bushing until it is removed entirely from the arm. Once the operation is done, the control arm will be loosened. Then, you can free the press and take off the arm. Position the new control arm bushing into the lower control arm. Keep an eye on the marks from the old bushing. Make sure to not lubricate the bushing case it will let the bushing get loose.
Straighten the press and carefully push the new lower control arm bushing into position. The bushing has to stay straight during the primary press so it cannot dismantle the housing. When the press has started the lower control arm bushing will remain straight.
Check the installation to ensure you have done it right and repeat it on the other unit. One full lower control arm can be installed now.
Step 6: Reinstall The Lower Control Arm
Hold the rebuilt or new lower control arm, and push the bushing into its associated frame mounts. You may have to do an up and down movement to help with the process. As you install the arm, observe the bolt holes to properly align them and place them back into their holes. Use a screwdriver to do this as it will be difficult without tools.
Once aligned, push the mounting bolts into the slot by hand to prevent cross-threading. Do not over-tighten the bolts till all the bolts are started. Place the lower ball joint and wedge it into the control arm. You have to install the nut manually now. Push the sway bar link inside the control arm and reset the nut and sway bar link.
Once the nuts and bolts have been installed you can secure the front arm mounting bolts. Follow the torque specifications of the manufacturer which is generally between 65 to 75-foot pounds. This is when a universal socket and extension would be very helpful. Align the cotter pin holes while tightening the lower ball joint castle nut.
A universal socket and extension can help when tightening the control arm bolts.
When you have tightened the nut, push the cotter pin. A cotter pin is needed to secure the nut in place. Keep the sway bar link straight while fastening the nut with a socket or wrench and you are all done!
Reassemble the wheel and bring the vehicle off the jack stands. We strongly recommend you keep the car aligned during this stage. When you first drive the vehicle after the repair, listen for weird noises which are an indication that the job will have to be examined.
Can You Fix A Noisy Lower Control Arm Bushing Without Replacing It?
In the event of a loose bushing, chances are high that it was either not installed properly or was knocked loose. If you are lucky, you will be able to salvage it by simply tightening the bushing. However, in most scenarios, the culprit is a worn bushing that will require replacement. Either way, take your vehicle for a check at a mechanic so they can do the replacement or repair for you.
It is not a good idea to ignore the knocking or clunking sounds coming from your vehicle as it can lead to a steering issue where your vehicle will go out of control on the road. Try to resolve the issue at your earliest convenience.
Lower Control Arm Bushing Replacement
You should try replacing all the control arm bushings at the same time, even if only one is worn. The others are likely to follow suit soon. Inspect the bushings for visible damage like hollowing or tearing of the rubber. Check the ball joints when the lower control arm bushing replacement is done. Which bushing should be used to replace the failed one depends on how you plan on using your vehicle. Original equipment (OE) bushings are constructed of rubber and deliver the comfiest driving experience.
In contrast, aftermarket performance bushings normally raise handling precision but may also make the ride firmer. These require regular lubrication for best functioning because the lubricant dissipates over time. A few aftermarket bushings are constructed of steel and are only good for certain flat race tracks since they give no control over shaking.
Lower Control Arm Bushing Replacement Cost
Replacing an upper or lower control arm can cost you anywhere between $160 and $390 for 1 arm. However, often, if one arm has gone bad, the other control arm will need replacement very soon. In this case, it is best to replace both of them at the same time. After 1 or both lower control arm bushings are changed, the wheel alignment process has to be performed (about $60 to $120).
Should you replace the stabilizer bar links along with the lower control arm? The stabilizer bar is generally linked to the lower control arms through stabilizer bar links. Occasionally, a nut that secures the stabilizer bar link can get seized and it would be impossible to retrieve it without damaging the joint. In this case, you may have to replace the stabilizer bar links too. In most vehicles, these links are quite cheap and do not need any additional labor hours to get done.
Worn-out lower control arm bushings can also be replaced individually. But, these need to be pressed in place using a special press or tool, which takes a little time and counts as labor cost.
On a difficulty scale of 1 to 10, changing a lower control arm on your own gets a 7 or 8. It takes about an hour or two to replace a control arm in the shop.
Aftermarket Vs OEM parts
Although aftermarket parts are more inexpensive, they are notorious for displaying signs of accelerated wear and tear. Our advice is to consider the quality over price when shipping for control arm bushing. These components contribute heavily to safe rides, especially in trucks and heavy SUVs. Use top-notch aftermarket parts or OEM components.
The reason why we keep emphasizing the importance of properly working the lower control arm and control arm bushings is that you should need a soft steering input.
Is It Safe To Drive With A Bad Control Arm
You should not drive with a bad lower control arm as it is dangerous and unsafe. At any moment you may lose control of the steering wheel, causing your vehicle to pull to one side and possibly resulting in a collision. If you are cruising on the highway at 65, you do not need one more distraction added to the list; there are plenty of cars and trucks around you for that. Adding a malfunctioning control bushing makes it riskier.
When a small component can make all the difference in your vehicle, it is foolish to take it lightly. The lower control arm bushing plays a key role in a vehicle’s suspension system. Whenever you hear a clunking noise, prioritize getting that checked before everything else.
Frequently Asked Questions (FAQs)
What Is A Bushing
Bushings are similar to narrow tubes most frequently used for equipment with sliding or rotating shafts to reduce noise and vibrations while improving efficiency.
How To Remove Lower Control Arm Bushing
To remove the lower control arm bushing you will need a hydraulic press. This releases rigid joints.
How To Replace Lower Control Arm Bushing
Follow the “Bushing Repair” guide above to learn how to replace the lower control arm bushing or check out this video.