1989-1998 Nissan 240SX Rear Subframe Bushing : Megan Racing
The black section on the outside of the bushing. It's not the metal sleeve you're talking about. It's the actual sleeve that holds the bushing into the subframe.
The subframe has it's outer section, then an inner sleeve, the bushing, and then the center sleeve (for the bolt), I broke the inner sleeve out, the one on the outside of these bushings. I didn't know I needed them for the ES Poly Kit...