The Dupont linkage has oiled bronze bushings for each end of the upper and lower arms. Each of these have a grease fitting.
The spring retainer welded on the center of the spring rod keeps the spring rod centered in the Dupont linkage. The spring rod passes through oiled bronze bushings in each of the spring end pivots. The spring end pivot rotates in the upper linkage arm as the Dupont linkage cycles through it's motion allowing the springs to stay straight. Since the spring rod passes through both springs any broken springs would be retained on the rod. In fact if a spring broke, the Dupont linkage would still operate.
This Dupont linkage is designed so that the springs cannot be compressed more than their specified maximum operating compression. The springs chosen have a longer range of operating compression than most and should give a very long life.