My experience using OEM and Aftermarket T-Rods; in various combinations with OEM vs. Eibach springs; and OEM vs Aftermarket FUCAs; clearly demonstrated that Aftermarket T-Rods are a significant source of jarring impact harshness into the cabin. I am convinced the spherical rod bearings are the source of this problem; and am also convinced it is the reason the OEM units use the silicon filled bushings.