How to Troubleshoot a Toyota Control Arm
The control arm of your Toyota is an essential front suspension component. Shaped like a letter "L" or "A", it's the part that connects the steering knuckle to your vehicle's chassis. In turn, the knuckle holds the front wheel in place. The control arm also helps with the suspension's up-and-down movement by being attached to control arm bushings, which are flexible rubber bushings responsible for the bobbing suspension motion.
This component is also responsible for letting the front wheels turn, this time by having its outer end attached to the steering knuckle via ball joint. There are some cars with a control arm that's merely a single link, with a rubber bushing on one end and a ball joint on the other end. All the same, no car can safely be driven once this part gets bent, damaged, or worn out.
Common symptoms of a compromised control arm
If you're hearing clunking or popping noises when your Toyota vehicle goes over bumps, there's a possibility that your control arm bushings and/or ball joint and spindle have been worn out or torn. You can also hear these sounds when you're decelerating or accelerating. This is also the case when your car feels unstable while braking or traveling over bumps. A warped, bent, or broken control arm could also lead to further complications, such as you losing a wheel while driving.
Worn-out or torn arm bushings
Unlike the ball joint that's often fused with the control arm itself, the bushing can be replaced separately. But this won't be cheap since on top of buying a new replacement bushing, you'll also have to pay for labor costs to have it installed competently. However, there are many other Toyota cars out there wherein when the bushing goes, so too will the control arm.
Separated ball joint
Because the control arm is responsible for holding both front wheels together with your Toyota's chassis, you're in deep trouble once the ball joint becomes separated from this arm (especially if you're driving at high speeds when this were to happen). Once the ball joint is separated, you'll need to replace the whole control arm assembly more often than not because for most cars, this joint is built right into the arm, so they could form one part rather than two separate, replaceable components. Even if the ball joint exhibits just the slightest of wear and tear, the safe and commonsensical thing to do is replace the entire assembly.
Control arm inspection and replacement
To know what exactly is wrong with your control arm, you'll need to inspect it from under the hood; you might have to hoist your Toyota up on a lift at an auto repair shop. You also have the choice of going under the vehicle lifted up by a jack and jack stands so that you can flash a light at the control arm and visually check its condition out by yourself.
There are also vehicle models wherein the control arm, ball joint, and bushings can be seen in the wheel under the hood or by looking under the wheel from beneath your car's fender. Specifically look for cracks on the rubber insulator, warping on the control arm, and damage on the ball joint and spindle. If one arm fails, it's likely you'll need to replace the other one soon.