News to me- - -but I always use original equipment parts whenever possible. The original bushing is flanged on only one side, and press-fits into the control arm. The rubber bushings are supposed to be bonded to both steel sleeves, and the suspension movement is absorbed by the rubber part flexing. I can't imagine why the polyurethane bushings would be used, if the control arm just rotates over it. I've changed hundreds of suspension bushings, and never left half a bushing in the control arm!
Jerry
Jerry,
I'm not sure I understand what you mean. I'm sure that I've installed my new bushings correctly, yet am always willing to learn from others.
I'm in the process of doing the driver's side now, so I'll post a few pics.
Jay