The new 38T front diff crown gear for the XB8 is CNC-machined from hardened HUDY steel developed specially for gears, allowing for ultra-true, vibration-free running. All edges are chamfered for smooth engagement. The "38" symbol is laser-engraved for easy recognition, as well as the bearing size is ground for maximum precision. Using this gear in the front diff of your XB8 alters the gear ratio from 3.333 (with 40T original gear) to 3.167. This makes the car easier to drive, especially in bumpy condition, and improves on-power stability. The new 38T front diff crown gear improves traction and reduces sliding.