This 5 ton kingpin support kit reinforces factory kingpins with a second set of kingpins. These 2 5/8 diameter 4140 chrome moly steel kingpins provide support in all directions. Top kingpin also takes upward thrust loads from abusive offroad conditions by dividing the thrust load between the top and bottom kingpins helping to eliminate knuckle stretch. This kit improves upon the factory setup that applies all thrust load to lower kingpin only. $2,400.00. Kit price includes all 4 kingpins, brackets and hardware – upper and lower.