After seeing multiple incidences of failure at the ball joint end of the factory 3rd gen 4Runner lower control arms, I designed a system of reinforcement plates to combat cracking from hard & repeated upward compression.
The issue is that while the LBJ support arm is forged and pretty stout, the arm itself is formed sheet steel – and when the bump stop meets the frame, the sheet steel is supposed to stop the upward travel of the wheel/LBJ. Over time and hard use, it cracks.
This kit includes 3 parts for each arm: a single upper reinforcement ties the forged ball joint arm directly to the bump stop mount to create a direct load path in order to reduce flexing at the end of the factory arm; while the lower two-piece reinforcement both adds triangulation from the bottom of the forged ball joint arm and incorporates a skid plate of the front side to slide the arm up and over obstacles while wheeling.
