The small lower strip of teflon has an adhesive side, its wafer thin. If you loosen the heim bolts when installing then tighten after the lid is bolted on it all comes together nicely. Re-pack with grease after very ride. The idea is to wear the teflon shims rather then the box. Ive done over 500 miles with the teflon installed & the box still has minimal play. I also tapped 2 bolts in the steering boss for less movement. The steering uni's also have a little movement.