Here is an exploded view of the Synergy tie-rod ends. You can see the sintered metal-on-metal bushing design that offers high wear resistance. Parts store tie-rod ends use a nylon bushing. The Synergy part also has added material where it counts, features a grease groove for maximum lubrication, and a spring-loaded design that keeps the joint tight as the part wears. Also, the joint is fully greaseable and that clear boot is made of tear-and-wear-resistant silicon and polyurethane.