About Ball Joint Tools If you are new to car mechanics, you may not be familiar with ball joint tools. These tool kits are specifically designed to allow professional and amateur mechanics work with a car's ball joint. The ball joint is a spherical part that is part of a car's suspension and steering system. Nearly ever make and model of car on the road uses some version of this part, which functions similarly to the ball-and-socket system of the human hip. The unique shape and overall design of this common automotive part means that you will have to have a special tool in order to work with the ball joint, and because ball joint sizes and shapes may vary by car, it may be necessary for you to invest in a full ball joint tool kit if you plan on working on a lot of different cars. These kits typically include multiple pieces of equipment that are used to remove and install ball joints. There is a vast inventory of ball joint tools on eBay, including full tool kits.