Traxxas replacement idle gear parts for the T-Maxx Replacement 16 Tooth Steel Idler Gear for the Traxxas T-Maxx 4WD Radio Control Monster Truck. This idler gear is installed in the gearbox and meshes with the Primary Gears. Replaces damaged or worn idler gears. Made of steel. INCLUDED: One 16 Tooth Steel Idler Gear for the Traxxas T-Maxx Truck. One 3x6mm and one 8.3x8mm flat metal washers. One 8x12x0.5mm teflon washer. One 3mm nylon locknut. One 3x20mm cap hex screw Required Parts Installing in gearbox over the primary gear shaft