A lower ball joint and upper floating king-pin make up the ball joints.
The upper ball joint serves as a pivot point that determines the axis on which the knuckle will move and thus, only experiences a lateral load.
The lower ball joint tracks the knuckle on an imperfect axis; the spherical lower is necessary to allow the knuckle to move freely with only slight vertical travel through its steering cycle.
Carli Extreme-Duty Upper Ball Joints have a pin and housing, but the “hat” of the pin contacts the housing.
This adds a second wear surface to distribute the load applied laterally to the ball joint while providing the same failsafe as a factory ball joint, ensuring the pin cannot be pulled through the bottom of the ball joint housing.
Furthermore, there is no sleeve isolating the wear surfaces, which eliminates the point of failure.
A Viton Seal at the bottom of the housing prevents environmental elements from entering the ball joint.
The lower joints have no liners of any kind.
At the top, a bronze wear surface preloaded by a disc spring, safety washer, and snap ring ensures the ball joints' wear surfaces are always held tightly together for superior performance.
The impressive durability and performance of Carli Extreme-Duty Ball Joints are significantly influenced by materials and processes.
It begins with masking; all surfaces except the wear surface are masked with copper plating.
Once plated, the ball joints proceed to carburizing.
The carburizing creates an extremely hard surface with a case-hardness (penetrating depth) of 20-25 thousandths.
After the carburizing/heat treatment is complete, the ball joint is stripped of the copper masking, leaving the entire joint heat treated and the wear surfaces incredibly hard.
Finally, the entire joint is covered with a corrosion-resistant gray coating for protection from the elements.
