Description HEAVY DUTY REPLACEMENT BALL JOINTS JEEP TJ/XJ/YJ (1987-2006)   10642    By Rough Country FEATURES Set of 4 ball joints (2 Upper & 2 Lower) Fit Dana 30 & Dana 44 Axles. Chromoly Ball Stud. Polyurethane Dust Boot. Carburized Alloy Housing. Heavy Duty OE Upgrade. Greasable. Works with all aftermarket axle shafts. Metal on metal design. NOTES – IMPORTANT There is a break-in period for metal on metal ball joints, typically during the first 100-500 miles the steering may be hesitant to return to centre and have a heavier feel. After break-in, the steering will feel tight and smooth.