🔧 Elevate Your Ride with Confidence! Includes 2 upper and 2 lower ball joints for a comprehensive upgrade. Enjoy a 12-month unlimited warranty for worry-free adventures. Experience seamless performance with our induction heat-treated bearing surface. Say goodbye to wear and tear with our tear-resistant silicone polyurethane boot. Crafted from larger-than-stock 4140 steel for maximum strength and longevity. Greasable design Silicone boot 4140 steel The Synergy Mfg Heavy Duty Ball Joint Kit for Jeep Wrangler JK is engineered for superior performance and durability. Featuring a fully greasable metal-on-metal design, this kit eliminates the stock nylon liner, ensuring a longer lifespan and smoother operation. Made from robust 4140 steel with an induction heat-treated bearing surface, it includes two upper and two lower ball joints, all backed by a 12-month unlimited warranty.