The support kit can be installed on pitman and idler arms showing a lot of wear, and actually revive them! If the worn parts have approximately 40,000 miles or less on them with a close to stock size tire, they probably will not have to be changed. If the worn parts have them with a close to stock size tire, they probably will not have to be changed. If the worn parts have approximately 20,000 miles or less on them with larger than 33" tires, they probably will not have to be changed. If the parts have more miles than that on them, it is recommended to replace the pitman and idler arms with factory units and add the Cognito Motorsports pitman and idler arm support kit.