Outfit your Jeep Wrangler JK or Grand Cherokee WJ with the last set of ball joints you will ever need! TheSynergy Manufacturing HD Adjustable Ball Joint Kitare a highly anticipated ball joint solution. Synergy spent five years and over 100k miles testing and fine tuning these ball joints. The finished product lives up to their HD name, and is specifically designed to tighten up sloppy steering. Unlike other Jeep ball joints on the market, the lower ball joints in this kit are adjustable for precise preload. They also feature CNC machined 4140 steel bearing surfaces, and can be completely rebuilt without being removed from the vehicle. Because of their low-profile design, Synergy Manufacturing HD Adjustable Ball Joints are compatible with RCV axles. Kit Includes:- One (1) upper ball joint pair- One (1) lower ball joint pair- Grease zerk fittings- Adjustment wrench- Installation instructions HD construction 4140 steel construction CNC machined When replacing factory style ball joints, the non-knurled version should be selected Complete kit Limited lifetime warranty Estimated installation time: 3-5 hours Fits:Jeep Wrangler JK 2 Door (2007-2018)Jeep Wrangler JK 4 Door Unlimited (2007-2018)Jeep Grand Cherokee WJ (1999-2004)