Two problems related to ball joint have been reported for the 2004 Jeep Wrangler. The most recently reported issues are listed below.
2004 Jeep rubicon ball joint failure.
Vehicle will enter into a violent wobble and shake when hitting a bump at highway speed. Violent shaking does not stop until speed is reduced to under 20 mph. Had wheels rotated and balanced, wheels aligned. Checked all tie rods, ball joints, and linkage with no noticeable wear. Death wobble still present.