I removed the bad hangers and pins and replaced with about good as new parts. I ground the rivet heads flat from the bottom and drove a pin with a hammer up until they popped out. Replaced new hangers with grade 8 bolts. I soaked the pins in gas and worked out all the old grease. I used a 2x4 and wedged it from the springs right next to the axle straight up to the frame. The board was a little long and I had to wedge it with a hammer. When I removed the shackle the spring rose maybe an inch. I was all scared for nothing. I put some grease on the threads, screwed them in, replaced the shackles, and greased the fittings. It was a satisfying sound to hear that grease flow through those pins. It did take a little muscle to get everything back together, but not too bad. Still cleaning frame and prepping for paint.
