What is a Ball Joint and Why We Need to Replace?

Ball joint failure isn’t a common problem, but can be the result of years of driving along bumpy, uneven road surfaces. A broken ball joint may be the cause of a mysterious clunking noise or drifting steering. And once they’re worn, they will seriously affect your steering and suspension. If a ball joint fails completely, it can even result in the wheel dramatically falling off the car. A scary thought! But what are ball joints and when do you need to replace them?


What is a Ball Joint?

Ball joints are sphere-shaped bearings connected to the control arms of the steering knuckle. It has a socket and steel bearing stud enclosed in a case. The bearing stud is shaped and threaded and fits into a shaped hole in the steering knuckle.


The Job of a Ball Joint.

Ball joint connect the car wheels to the suspension system, and allow them to move together. As the name suggests, these clever ball-and-sockets acts as a pivot, similar to the hip joint in the human body. Ball joints are made of a bearing stud and socket that fit snugly inside a lubricated casing. They connect the control arm to the steering knuckles and allow for smooth and solid movement in the suspension. The front suspension of most cars has at least lower ball joints and in some cases upper ones as well.

How to Know Ball Joints Are Worn

At the Shop

Most worn ball joints will be found during yearly state inspections or during a routine service check at the shop. The technician “shakes” the front end of the car while it is on a lift (off the ground). When moving a tire slowly from side to side and up and down, worn parts will have exaggerated movement or “play” which indicates they are worn.

Symptoms While Driving

While making a slow sharp turn, a worn ball joint will make a snapping sound. Think of the ball being pulled from the socket then released.
Likewise, a quick look at your tires may reveal worn ball joints or other front end components. Any uneven wear should merit a trip to the shop for a check over.


Symptoms of Bad Ball Joints

Most modern cars have ball joints that are made to last the life of your car, but damage and wear and tear can cause them to stop working properly. This is especially true for cars that are driven regularly on bumpy or unmaintained roads, and cars that are used in constant, stop-and-go city traffic.

If that’s the case for you, have the ball joints inspected during oil changes to keep an eye on them and their performance.

Bad ball joints aren’t just a nuisance — they can compromise your steering ability and make it dangerous to drive. Look out for these signs that something’s wrong:

  • Clunking noises. A worn ball joint will begin to rattle inside its housing, which causes a metallic clunking sound whenever the suspension moves up and down over bumpy or uneven roads.
  • Squeaking. If the rubber boot that contains and protects the grease becomes damaged, you’ll begin to hear a squeaking sound when you turn. This is due to the joint losing the lubrication that normally keeps it quiet and smooth.
  • Vibrations.Loose or worn ball joints will cause excessive vibration. You’ll feel the steering wheel or the vehicle’s body shake.
  • Pulling to the side when driving. A loose ball joint will affect the car’s alignment, causing it to pull to the right or left as you’re driving.
  • Loose or shaky steering. Bad ball joints can cause a car to feel shaky and unstable. This symptom is especially worrisome because it can cause drivers to feel like they don’t have control over their vehicle, possibly resulting in accidents.
  • Uneven tire wear. Since bad ball joints can knock the car out of alignment, you might see uneven tire wear due to the imbalance. Uneven tire tread shows up as inconsistent stripes of thinner tread on each tire. You might see a visual difference, or notice varying depths when using a tire gauge.


Can We Replace Ball Joints Ourselves

If you’re feeling handy and want to tackle a reasonably easy repair, replacing your ball joints is a great way to scratch the itch.

You can certainly do it yourself for the price of parts, and a bit of elbow grease. You will need a ball joint press, but you should be able to buy one of these from OrionMotorTech.


How Often Should Ball Joints be Replaced?

Typically, your ball joints will need to be replaced after 100,000 miles, although this depends on the conditions you typically drive in. A safe range is anywhere between 75,000 to 125,000 miles. On newer vehicles, ball joints don’t need to be replaced as often.

In older vehicles, the boot covering the joint is more apt to tear and allow grime into the joint itself, which can cause it to seize up. The load-bearing ball joints in your vehicle will wear sooner than the non-load-bearing joints.


There is not much we can do to prevent ball joints, or any other front-end part, from wearing out.

Some ball joints come with grease fittings where newer, cleaner grease can be periodically added to tighten up small spaces and lengthen service time, but these fittings are typical of older model cars. The best strategy is to keep up with repairs on the suspension in order to slow the overall wear.