A basic introduction to ball joints

Ball joints are vital components of a car’s chassis and suspension system, and are subject to wear over the life of a vehicle. To put it simply, ball joints are used to allow the front wheels and tires to pivot on a vertical axis as you turn the steering wheel one way or the other. Believe it or not, you’re body has built in ball joints as well. Just think of your legs and arms. One end of your arms and legs have a ball of sorts, that sits within the cups of your hips and shoulders. Even this are subject to wear, as sometimes humans have to undergo shoulder or hip replacement. The same idea carries over to the cars that you see on the road today.

Ball Joints don’t have a generalized replacement schedule, as they are commonly replaced only when they fail or are found to be worn to the point of needing replacement. Over years of use, the pivoting ball hidden behind the dust boot of the ball will wear down and become “loose.” This means they have a lot of play in them and could eventually separate altogether if not replaced in time. It’s important to stay on top of this as a ball joint failing while you’re driving could lead to an accident.

So, now that you know what they are, you’re probably wondering what signs to look for. Keep on reading to learn more about them.

Where Did all of this Grease Come From?

What are Ball Joints and When Should They be Replaced?
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To prevent premature wear, each ball joint assembly is packed with grease as a lubricant. Sometimes the boots that hold this grease inside the ball joint will get ripped or damaged. As such the grease inside can ooze out onto other parts of the chassis. Even if the ball joint isn’t worn enough to warrant replacement, it will be soon, so it’s better to replace them now than to wait for them to fail.

Why is That Tire Leaning

The stud of a ball joint, when new, when new can pivot in all directions under pressure, but as they fail, the weight of the car can cause them to shift and point in one direction or another. One way of noticing you have a ball joint that is excessively worn is if your tires lean inward out outward at the top or bottom. This can also be the result of bad alignment, but it’s troublesome and should be inspected right away.

Does the Wheel Wiggle in the Air?

Check for play or wear in a ball joint is actually really easy. With one end of a tire lifted off the ground, and can wiggle the wheel and tire from the top and bottom. Good ball joints won’t have any play. When the ball joints are worn, you’ll be able to wiggle the wheel and tire. For something that’s vital to your car’s safety, they are very easy to check.

Tools for the Job

When it comes to checking ball joints, you don’t need anything other than a jack to go with a pair of jack stands and a pair of wheel chocks for safety. These tools are rather cheap to purchase for the occasional dIYer. For most smaller cars, the products shown below will work perfect and don’t hit the bank for much. Through Amazon, you can the everything you need to get your car’s front end into the air for less than $70 with shipping.

2-Ton Floor Jack

What are Ball Joints and When Should They be Replaced?
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Most small and midsize cars can be lifted with a basic two-ton floor jack. These jacks are inherently safer than the scissor jacks included with new cars as they provide more stability. The one you see here can be found on Amazon for $29.99 as of the time of this writing. Click here to check it out the details or to order one for yourself.

Jack Stands

What are Ball Joints and When Should They be Replaced?
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Jacks should only be used for lifting. Never work on a car only supported by a jack. With that said, you’ll also need a pair of jack stands to rest the front end of your car on while you check out your ball joints. The jack stands you see from Torin here have good reviews and are priced at $18.55 as of the time of this writing. Check them out or order them here.

Wheel Chocks

What are Ball Joints and When Should They be Replaced?
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Even if you have an automatic transmission and a working parking brake, it’s always important to be as safe as possible. A pair of wheel chocks placed around one of the rear wheels will help to stop the car from rolling forward or backward in the event that the parking brake fails. The pair you see here are plastic and light duty, but should work fine as a back-up on smaller cars. Priced at $5.04, they aren’t a bad buy, but if you have anything larger than a BMW 3 Series or a Chevy Cruze, you’ll want to move up to something that is all rubber or metal. Check out this light-duty pair or order them here.

Robert Moore
Editor-in-Chief and Automotive Expert - robert@topsped.com
Robert has been an auto enthusiast his entire life. He started working cars at a young age, learning the basics from his father in the home garage on the weekends. As time went on, Robert became more and more interested in cars and convinced his father to teach him how to drive when he was just 13 years old. Robert continued working on cars in his free time and learned as much as he could about engines, transmissions, and car electrical systems, something that only fed his curiosity more and eventually led him to earn a bachelors degree in automotive technology with a primary focus on engine performance and transmission rebuilding.  Read More
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