Traxxas pivot balls and bushings for the E-Maxx and T-Maxx (4) For the Traxxas T-Maxx and E-Maxx 4WD Radio Control Monster Trucks. INCLUDED: Four pivot balls, steel and Four pivot ball cap bushings, plastic. Pivot balls fit into the axle carriers at each wheel. The pivot ball cap bushings fit between the pivot balls and the aluminum caps. "