Moog K500188 Ball Joint Problem Solver patented cover plate design allows for tighter tolerances vs. traditional cover plate designs, providing a more durable and extended life part. Exclusive cover plate protects against contaminants leaking into the bearing surface. Moog engineered steel composition results in a stronger component Sealed boot with a grease relief valve prevents contamination and releases excess grease away from brake components. Greaseable socket design allows new lubricant to flush contaminants from the assembly, reducing corrosion and wear Loose or worn chassis parts can lead to premature tire wear MOOGCHASSIS K500188 BALLJOINT