Moog CK8728T Control Arm and Ball Joint Assembly 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. Exclusive double bearing allows for less preload, resulting in reduced steering effort. Problem Solver patented cover plate design allows for tighter tolerances vs traditional cover plate designs, providing a more durable and extended life part. Moog engineered steel composition results in a stronger component Full ball metal stud provides 36 degrees of smooth, consistent, rotational movement resulting in more responsive steering. Grease release polyurethane boot lasts longer and directs contaminants out of socket and away from brake components during lubrication. Greaseable socket design allows new lubricant to flush contaminants from the assembly, reducing corrosion and wear