Moog K80591 Ball Joint Problem Solver powdered metal gusher bearing design enables grease to flow through the bearing to the stud for reduced friction and enhanced strength and stability. Full ball metal stud provides 36 degrees of smooth, consistent, rotational movement resulting in more responsive steering. Greaseable socket design allows new lubricant to flush contaminants from the assembly, reducing corrosion and wear Moog engineered steel composition results in a stronger component Polyurethane boot offers durability and resistance to extreme temperatures. Loose or worn chassis parts can lead to premature tire wear