This 12JSDX240TA-1707030 splitter pinion gear fits FAST 12JSDX240TA 12-speed heavy-duty transmission. It is installed in the auxiliary splitter box to transmit torque for high-low range shifting. Made of 20CrMnTi alloy steel, precision grinding and shot peening strengthen gear tooth surface. High hardness, outstanding wear resistance, strong capacity for heavy torque and impact load. Works reliably under long-distance heavy haul, mountain roads and frequent range shifts. Each gear passes dimension, tooth profile, runout and hardness inspection before shipment. Solves auxiliary box gear chipping, abnormal noise and power interruption faults. Essential OEM replacement spare part for 12JSDX240TA gearbox overhaul.