The function of the control arms of your vehicle is to connect the wheels to the frame and function as an essential part of the suspension system. The control arm acts as a mounting point for the wheel and complete suspension assembly. Due to their location, control arms are constantly subjected to harsh environments, road debris, and shocks. Over time, this leads to wear, and you have to replace your control arms.
However, if you are planning to replace the control arm yourself, it can be difficult and tricky if the parts are corroded or if the ball joint is damaged. Replacing a control arm requires a little experience and some tools, but can be easy if you have worked on your vehicle before. If you are witnessing symptoms of control arm failure, you should install a new control arm. This stepwise control arm replacement guide will help you replace your old, worn-out control arm with a new one.
1 How To Replace The Lower Control Arm?
Replacing your lower control arm is fairly easy and straightforward in most passenger cars. It depends on the suspension design and the type of vehicle you own. For example, it is difficult to work on a vehicle with a torsion bar and should be left to a professional mechanic. In this guide, we will learn how to replace the lower control arm on a vehicle with a MacPherson suspension system or double wishbone suspension system, which is mostly used in off-road vehicles and SUVs. Also, to ensure a hassle-free and perfect installation, it’s important to purchase the correct lower control arm. Refer to our comprehensive control arm buying guide to purchase the correct part for your vehicle.
2 Remove The Wheel
First, loosen the lug nuts but do not remove them completely. Secure the wheel by leaving a lug nut on so that the wheel doesn’t fall unexpectedly when you lift the car with a jack. Position the jack according to the owner’s manual’s instructions for changing a tire. Lift the car using the jack, and place the jack stands under the car for stability. Remove the bolts that secure the wheel and remove the wheel.
Use jack stands to secure the car, and do not attempt to secure the car only on jacks. It’s a good idea to place the wheels under the car to prevent injury in case the jack stand fails.
3 Remove The Ball Joint
Removing the wheel will expose the steering knuckle. Start with removing the ball joint. Remove the cotter pin (not every car has it), which is located below the castle nut, and lock the ball joint. Some cars have a pinch bolt instead of a castle nut. Use a wrench to loosen the nut or the pinch bolt after removing the cotter pin. You can use a screwdriver to create space between the pinch bolts so that the fit isn’t tight. Then, by using a hammer, strike the spindle or the control arm to remove the ball joint from the steering knuckle.
4 Remove The Sway Bar or Stabilizer Bar Link
A sway bar, also known as a stabilizer bar, is a long, U-shaped rod that prevents the vehicle from rolling over at corners. These are connected to the control arm with the help of a sway bar link. Remove the nut by holding it with a wrench or a socket and loosening the nut with a socket. After loosening it, you may need to shock it loose, just like you did with the ball joint. Remove it from the lower control arm mount so that plenty of space is available to do the next job.
5 Remove The Control Arm Mounting Bolts
The control arm is mounted to the frame or subframe of the vehicle by two bolts, which can be in a vertical or horizontal position. Some of them may have a nut on the backside, and you can loosen these bolts using a wrench and a breaker bar. After loosening these bolts, the arm may come loose and is ready to be removed from the vehicle. You might have to remove the engine splash shield to gain better access to the control arm bolts.
| Ford F150 (2004-2008) | To remove the upper control arm, use a 21mm socket to loosen the upper ball joint and a 21mm socket to loosen the other two bolts holding the control arm. |
| Dodge Ram 1500 (1994-2002) | Use a 21mm socket to loosen the nut holding the ball joint and the two nuts holding the control arm from the top. |
| Dodge Ram 1500 (2009-2018) | Use a 21mm socket to loosen the upper ball joint and the tie rod end, which will loosen the whole knuckle. Then use a 24mm socket to loosen the bolt from under the knuckle that holds it. Make sure to loosen the axle by using a 36mm socket before doing this. This will expose the control arm, then you can use a 24mm socket to loosen the front control arm bolts and a 24mm socket and wrench for the rear control arm bolts. |
| Chevrolet Silverado 1500 (2007-2015) | Use a 19mm wrench to loosen up the upper ball joint, and then loosen the two bolts holding the upper control arm with the help of a 21mm socket to hold the nut and a 21mm wrench to keep it from spinning. And for the lower control arm, first loosen the lower ball joint with a 22mm socket, and then loosen the two bolts holding the lower control arm with a 24mm wrench to loosen the nut and a 18mm socket to loosen the bolt. |
6 Install The New Control Arm
Grab your new control arm and inspect if the pre-fitted bushings are functioning properly and are greased. When installing the control arm, the first step is to align the bolt holes. It can be a little tricky as the other hole may get out of alignment. Use a screwdriver to align the holes and insert a new set of nuts and bolts. It is critical to replace your old control arm nuts and bolts because they may be rusted and rounded off. Hand-tighten the nuts and bolts.
7 Attach The Sway Bar Link And Ball Joint
Reattach the sway bar link you removed earlier. After doing this, insert the lower ball joint of the control arm into the steering knuckle. Ensure the ball joint is seated on the steering knuckle properly by using a hammer. Hand-tighten the castle nut or the pinch bolt that holds the control arm ball joint to the steering knuckle. Also, hand-tighten the sway bar link and other hardware.
Tighten all the control arm ball joints and sway bar nuts and bolts to the recommended torque specifications using a torque wrench. Insert the cotter pin underneath the ball joint and castle nut.
8 Reinstall The Wheels And Test Drive
Reinstall the wheel and hand-tighten the lug nuts. Remove the jack and jack stands and lower the vehicle. Tighten your lug nuts using a torque wrench. Finally, take the vehicle out for a short spin and drive it like you usually do. While doing so, listen for strange noises such as clunking, clicking, or squeaking, especially when the vehicle is accelerating, coming to a stop, or making a turn. If you notice no symptoms or noises, you have successfully installed your control arms.
Wheel Alignment
The last step is to align the wheels of your vehicle. It is important to get a wheel alignment done after replacing control arms or changing other suspension components. Refer to our DIY wheel alignment guide for more insights and why it’s important to perform wheel alignment periodically.
9 Upper Control Arm And How To Install It?
Most front-wheel drive vehicles, such as a hatchback or a sedan, are equipped with a lower control arm and a MacPherson strut suspension system. However, vehicles such as SUVs, off-road vehicles, trucks, and 4x4s have both upper and lower control arms to ensure balanced wheel control and stability. Vehicles with upper and lower control arms have a double wishbone suspension setup. The main difference between a double wishbone and a McPherson suspension system is that the MacPherson system makes the suspension very compact and the cabin more spacious, allowing room for passengers, the steering system, etc. MacPherson is mostly used on the front, and double wishbone is used on the rear. However, many SUVs, off-road vehicles, and performance cars use double wishbone suspension in the front because it offers better steering and handling compared to MacPherson struts with a single control arm.
10 How To Install A Upper Control Arm?
Similar to the lower control arm, the upper control arm has an identical installation process, which is as follows:
- Lift the vehicle and remove the wheels.
- Detach the ball joints situated on the top side by loosening the pinch bolts. You might need a hammer to pop out the ball joint of the control arm.
- Unlike the lower control arm, the sway bars are not connected to the upper control arm.
- Remove the two mounting bolts that connect the upper control arm to the frame.
- After removing the old control arm, make space for new ones. Check the pre-installed bushings on the new upper control arm.
- Install the new upper control arms and tighten them to the manufacturer’s recommended torque specification.
- Take out the vehicle for a short spin and look out for weird noises, which should be rectified soon.
11 Should Control Arms Be Replaced In Pairs?
The short answer is yes. If the left control arm is worn out or the bushing is torn and making noise, it’s safe to assume that the right control arm bushings are just as worn or will fail soon. Worn bushings can lead to abnormal tire wear, or the steering wheel may be off-center while the vehicle is traveling straight down the road. Changing the control arms in pairs is always a good idea, as it will save you future repair costs and new tires because of the uneven wear. While changing control arms, you can also replace your old bushings with new ones and go for polyurethane bushings, which offer better performance compared to rubber bushings. Read more about polyurethane vs rubber suspension bushings.
12 Should I Replace The Ball Joint Or Complete Control Arm With Ball Joint Assembly?
Some reasons why you should replace your complete control arm assembly instead of just the ball joints are mentioned below.
- Ball joints require special tools like ball joint press to install and remove the ball joints, which can be time-consuming and cumbersome. Whereas a complete control arm can be replaced using basic tools such as sockets and wrenches.
- Even if you change your ball joints, chances are that your control arm bushings are worn out too. This means you will have to repeat a lot of what you did to change the ball joints. It’s easier to change the whole control arm assembly than change the ball joints.
- Apart from all the reasons stated above, you can damage your control arm when replacing a ball joint. For example, beating it with a hammer or heating it can disrupt the structural integrity and weaken it or even bend it.
