I saw the same results on our last 5er. Bronze bushings wore right through.
On our new 5er when it comes time for replacement, If I don't go with Morryde Independent, I'm going with Roadmaster Comfort Ride Slipper Spring Systems. It eliminates alot of the flip flop movement since it gets rid of the entire center equalizer decreasing wear. Plenty of install videos on the YouTube to see how easy of an install it is. The large part gets fastened to the existing hanger plus gets bolted on the ends to the frame. The center section has rollers that aloow the springs to independently slide.
Edit: to add, they have kits available that will include shocks as well. I'd definitely go the extra bucks and have shocks too.
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