Excavator Pump Parts Ap2D25 Drive Shaft For Main Pump DX60 Spare Parts Our drive shaft is mainly the hydraulic main pump input shaft, which captures engine power to drive cylinder block rotation. Main Functions Transmit engine torque to support high‑speed cylinder block spinning Drive piston‑shoe assemblies to reciprocate for oil suction and discharge and deliver hydraulic energy Common Failures Worn splines and rolled keys: Power transfer slippage leads to insufficient pump