Rear Leaf Spring Insulator (E5TZ5A636A) by Ford OE. If you want to keep your Ford performing the way it did when it left the factory, rely on Ford OE products. Manufactured to strict specifications for fit, form, and function, they not only help restore original performance but also install in no time flat. No modifications needed! These products are sure to deliver the quality, reliability, and durability you expect from Ford.