The suspension of the automobile travels up and down while moving over the road surface. The control arm allows these movements to take place through the use of bushings. When the control arm has trouble, it affects the way the car drives. If you think you have a bad control arm, read on to learn the symptoms and what you can do about it:
What is a Control Arm?
The control arm (view on Amazon) is also often referred to as the ball joint or the control arm bushing and is typically manufactured in an L or A shape. Some vehicles may have two control arms on each wheel with a suspension spring mounted in between. The control arm enables wheel movements by connection to the steering knuckles with ball joints.
The control arm connects the wheel assembly and the frame while carrying the vehicle weight. Originally, the control arm bushing (view on Amazon) was manufactured with rubber materials and were designed to keep the control arm in alignment. Modern designs include the ball joint and bushing. When the control arm assembly is working properly, the vehicle rides smoothly with clean turns and no noise. When the assembly is not working properly, the steering and suspension no longer provide a smooth ride.
Causes of Bad Control Arm
Several things, including a bad control arm, can affect the steering and suspension system on the automobile. Two ends of the control arm may be connected to the chassis. The control arm that is unequal or has multi-link suspension requires less negative camber because the vehicles have more sophisticated engineering for faster, progressive rates of negative camber when cornering. The suspension system is attached to the vehicle with the control arms. Here are the most common reasons the control arm will go bad:
Wear and tear – All automotive parts are subject to wear and tear, especially the parts on vehicles that have been purchased used. Years of rough riding and fast driving is hard on the suspension and will eventually wear the control arm out. If the control arm itself is not worn, it could be the ball joints or bushing that have gone bad.
Lower arm bushing wear – The lower control arm must keep the lower control arm attached to the frame. The lower arm bushing is under constant stress and can be too loose or it can just become worn out just by years of constant use. The bushing must to be replaced once you start to hear a clunking sound.
Negligence – The lower control arm bushing is very fragile and oftentimes, it has been damaged in the course of a repair. This is especially common when the bushing is older and a bit worn. When the mechanic is not careful in handling the bushing, it can easily become damaged.
Symptoms of Bad Control Arm
The first signs of trouble with the control arm show up in the steering system and in the wheels. The comfortable riding, high performance, and the smooth handling all deteriorate when the control arm goes bad and problems grow in the suspension system. There are specific symptoms of a bad control arm and here are the most common:
Clunking noises – Sounds tell you that there is something wrong with the vehicle. The clunking noises from a bad control arm usually can be heard after riding over a bump in the road, making a hard turn, or braking. You will usually hear the strange clunking or popping noises coming from the steering wheel when turning the wheel or driving on uneven surfaces. This is caused by worn control arm bushings. The clunking noise will become louder the longer you drive with the problem, until the assembly completely breaks.
Wandering steering wheel – The steering will wander to the left or the right and perhaps will not return to the natural center. This is caused by a control arm assembly that is bad or is failing. More specifically, the ball joints and bushings have become worn which causes the vehicle to pull to the left or the right. More often, the steering problem is due to deteriorating upper control arm bushings. The bushing is designed to reduce the friction and the vibration which occurs in the mechanical joints. The bushing does wear over time, losing its elasticity or completely failing. This allows for the excessive movement in the suspension.
Uneven tire wear – The control arm assembly directly affects wheel camber. When the wheels have too much negative camber, they will wear at a faster rate. The tires will wear on the inside or outside in uneven patterns. The vehicle-to-pavement interface may be a part of the problem. The top edge of the wheel tilts in toward the center of the vehicle when the suspension attempts to compensate for induced roll which happens because the tire’s contact area with the road has been reduced.
Vibrations – Worn ball joints and bushings cause vibration as you drive down the road. Heavy vibrations are felt while riding down the road. Mostly the vibrations are coming from the steering wheel as the wheels are not rolling smoothly. The vibrations get worse when you accelerate.
Loss of performance – The vehicle with control arm problems no longer rides smooth. Besides hearing noises, the steering wheel is difficult to control and the vehicle vibrates. The experience is such a contrast to when everything is operating as it should, it is hard not to notice when the control arm has worn out.
What to Do About Bad Control Arm
The control arm is subject to wear and tear from excessive movement more so than many other parts to your car. Therefore, the control arms should be checked once a year. When the control arm stops functioning, it must be replaced. You may need to replace the entire control arm assembly, the ball joint, or the bushing. Here are the steps to replace the assembly, the ball joint, or the bushing:
Have a wheel alignment – Wheel alignments are recommended to slow down the wear and tear of the tires and to make sure the car drives straight on a level surface. Wheel alignments can also help to put the steering and the wheels back in sync. Regardless of what the problem is with the steering system and the suspension, it is never a bad idea to have the wheels aligned.
Maintenance to Avoid it – Most vehicle owners understand that a vehicle must be inspected and serviced from time to time, as referred to as routine maintenance. For those who don’t, the likelihood of problems that cause a damaged control arm is extremely high. If the vehicle is not inspected routinely, small problems can escalate to major problems that are much more expensive to fix. This is also true for vehicles which sit for long periods of time.
If you want to avoid a bad control arm or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.
A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.
Replace the control arm assembly – Replacing the control arm is not a very complex procedure. It also improves performance and prolongs the life of your vehicle. If you must replace the control arm itself, follow these steps:
1. Lift the vehicle up on a lift.
2. Remove the front wheels.
3. Disconnect the control arm where the sway bar and bushels are joined.
4. Disconnect the lower control arm from the steering knuckle and the wheel hub.
5. Remove the bolts and remove the control arm from the frame.
6. Fit the new control arm and install.
7. Replace the front wheels.
8. Have the wheels aligned.
Replace the ball joint – Ball joint replacement will vary depending on the type of vehicle. In any vehicle, the rubber boot is a part of the problem. The boot can split and leak. Inspect the ball joint for movement. If the ball joint needs to be replaced, follow these steps:
1. Check your owner’s manual for the ball joint installation recommendations, TSBs, and torque specs.
2. Gather your materials: Ball joint press kit; socket air tools, socket, torque, extension, and ratchet wrenches, ball joint separator, rust penetrant, shop towels, hammer, axle press, tire iron, screwdrivers, and needle nose pliers.
3. Use the side cutters to remove the cotter pin that secures the fastening nut.
4. Use the socket wrench to remove the fastening nut and axle nut.
5. Push the axle backwards and move the knuckle assembly around to loosen it so that you can access the ball joint.
6. Separate the ball joint from the lower control arm. Continue on to remove the ball joint.
7. Insert the new ball joint into the knuckle assembly and then check to make sure it is level.
8. Fit the adapter over the top of the ball joint.
9. Wind the press to tighten the assembly by hand.
10. Work the axle shaft back into the wheel bearing and apply rust penetrant to slide it in.
11. Reapply the fastener nut and the cotter pin.
12. Make sure to take the car to have a wheel alignment after the ball joint replacement.
Replace the control arm bushings – First, do a visual inspection of the vehicle. Look for bushings that are worn. Take a hold of the components in the suspension and try to jiggle them around. If you hear rattling noises, the bushings need to be replaced.
Replacing the bushing is pretty simple in most makes and models. To replace the rubber bushings, follow these steps:
1. Gather your materials. You will need goggles, gloves, a socket and extension, car jack, a large wrench, hammer, and hydraulic press.
2. Put on the safety gear, which should include the gloves and goggle.
3. Remove the tire.
4. Locate the ball joint. The ball joint is probably connected to the control arm. Release the cotter pin and loosen the ball joint nut with the wrench.
5. Strike on the spindle with a hammer to release the taper fit.
6. Use the wrench to loosen and completely release the sway bar.
7. Use the wrench to loosen the control mounting bolts. Remove them.
8. Pull on the lower control arm to loosen it and remove it.
9. Place a mark on the spot of the orientation of the rubber bushing.
10. Use a hydraulic press or a threaded press to remove the bushing.
11. Strike on the old bushing to remove it. Push out any excess rubber in the socket.
12. Install the new bushing in the control arm.
13. Secure the bushing with the hydraulic press.
14. Reinstall the control arm by sliding it back into the mounts.
15. Replace the bolts and tighten the ball joint.
16. Reinstall the sway bar link and the nut. Tighten the mounting bolt.
17. Replace the nut with the socket and extension.
18. Replace the cotter pin in the holes aligned by the ball joint.
19. Replace the tire.
Go to a repair shop – Some degree of experience is required to perform the mechanical work on the control arm. If you do not have the tools or you cannot perform the repairs, take your car to an automotive repair shop where not only will the repairs be made, but the tires can be aligned also. Driving a car with a bad control arm is not safe. Have your vehicle repaired, get back on the road, and drive safe.