Today's vehicles use a front suspension system that uses upper and lower control arms to attach the wheels to your vehicle, or MacPherson struts and a control arm to mount the wheels. The hubs on which the wheels and tires are mounted are attached to the outer end of each control arm and move up and down as the control arm rotates, they usually remain vertical. The hubs are also attached to your steering system and must be able to rotate left and right at any point of up and down movement.

What is a ball joint and what do ball joints do?
Ball joints are an important part of modern automotive suspension systems. They are one of the main suspension pivot points that connect the vehicle's control arms to the steering knuckles or spindles. The front ball joints also allow the front wheels and suspension to move back and forth as well as up and down. They provide universal rotational movement between the wheels and control arms, providing you with a safe, smooth ride and giving you precise control of your vehicle.
Ball joints in the suspension allow jointed motion of the wheels without transferring that motion to the cabin. Ball joints are usually of a ball-in-socket design, lubricated with grease and covered with a dust cover. However, over time, these joints wear out. They may lose lubrication, loosen, or become completely stuck. What are the symptoms of a bad ball joint and how to tell if a ball joint is bad? Below, we've identified four important signs to look for. These signs indicate a problem with your vehicle's suspension, such as a loose or worn ball joint.
What are the most common signs of worn ball joints?
1. Bad ball joint sounds. A clanking, rattling noise.
Whenever you hear an irregular clanking, rattling or clicking sound coming from underneath your vehicle, there is a good chance that there is a loose part somewhere in the suspension. Ball joints are a common culprit. If the rattling is more pronounced when you're bumping and sinking down the road, then it's almost certainly coming from a suspension problem.
As a failing ball joint exhibits many of the same symptoms as other common problems. When this happens we recommend that you go to a mechanic to get a professional diagnosis that will completely resolve the problem with your car.
2. Excessive vibration at the front of the vehicle.
Worn ball joints will shake and rattle as you drive, causing excessive vibration in the suspension, usually on one side. Sometimes the vibration can be felt through the steering wheel.
3. The car wanders, steering to the left or right.
Steering drift, when one or more ball joints are damaged, the car will drift to the left or right. It may be difficult to distinguish between steering drift and poor alignment, as both conditions can cause the car to pull or drift to the left or right. However, steering drift can cause the car to drift left or right instead of pulling hard in one direction.
4. Uneven tire wear.
Irregular and/or excessive tire wear is an important indicator of ball and socket joint wear. Wear on the inside or outside of the tire is a strong indicator of a bad ball joint and can be difficult to catch; therefore, if you experience any other symptoms, be sure to inspect your tires carefully, especially on the inside of the tread. If wear occurs on both the inner and outer edges of the tread, it may not be due to a worn ball and socket joint, but rather an underinflated tire.
5. Wear Indicators
Some ball joints have a built-in wear indicator to ease the difficulty of trying to diagnose a loose ball joint. The wear indicator consists of a removable grease nipple. When the collar of the oiling nozzle is flush with or below the bottom of the ball joint housing, the ball joint is worn and should be replaced.
Other types of wear indicators have a pin protruding through a hole in the bottom of the ball joint. As long as the pin is visible, the ball joint is fine. When it is flush with the housing or not visible, the ball joint should be replaced.
How long do ball joints last and when should they be replaced?
Ball joints can last 70,000 to 150,000 miles or more. The service life depends on usage, road conditions and weather. If the joints wear out and show any of the symptoms mentioned in this article - clicking, knocking, rattling, steering drift and drifting, abnormal tire wear - they should be replaced.
When your car needs a ball joint replacement, we recommend that you choose to have a professional mechanic do the job. But if you're a home mechanic who likes to DIY at home, then buying a ball joint tool set at an auto parts market is the most economical option.Orion Motor Tech's premium ball joint tool set can meet the needs of all mechanics who want to do it themselves.
Ball Joints FAQ
Q1: What are ball joints and what do they do?
A1: Ball joints are crucial parts of your vehicle’s suspension, connecting control arms to steering knuckles. They allow your wheels to move up, down, left, and right, helping you have a smooth and safe ride.
Q2: What are the common signs of bad ball joints?
A2: Look out for clunking or rattling noises, excessive vibration in the front of the vehicle, your car drifting to the left or right while driving, and uneven tire wear.
Q3: Why does my car wander or drift while driving? Could bad ball joints be the cause?
A3: Yes, worn ball joints can cause your car to steer off-center or wander, making it harder to keep the vehicle straight.
Q4: How long do ball joints typically last? When should they be replaced?
A4: Ball joints generally last between 70,000 and 150,000 miles depending on driving conditions. If you notice any symptoms like noise, vibration, steering drift, or tire wear, it’s time for a check-up and possible replacement.
Q5: Can I replace ball joints myself or should I go to a mechanic?
A5: It’s best to have a professional mechanic replace them, but if you have the right tools and some mechanical know-how, you can do it yourself. Special ball joint tool sets can make the job easier.
Q6: How do wear indicators help tell if ball joints need replacing?
A6: Some ball joints have grease nipples or pins that show wear. If the grease nipple collar is flush or below the housing, or the wear pin is no longer visible, the ball joint likely needs replacement.