Removed all the springs and made sure the hangers were free with a total range of movement. The entire spring was separated, sandblasted, and inspected. In my case each spring had an imprint of the spring below due to heavy loads and years of wear. I used a grinder and beveled the upper edge of each leaf below the main spring therefore allowing good movement of the sping over the imprinted area. This bevel only needs to be on the end and angled edges. After a primer and final finish coat I assembled with a new 5/16 grade #8 bolt. The hex head of the bolt needs to be rounded to fit into the spring pearch. Try fitting the head into the spring pearch prior to assembly of the entire spring. When attaching the spring to the frame be sure your adjustments are set correctly so it will take grease.