Product Overview This hydraulic swing motor assembly is the core rotating drive component of the excavator, compatible with the E320GC model. It delivers torque for upper structure rotation and integrates the motor with the reduction gear into a single unit. Precision machining ensures stable rotating output and reliable sealing performance, making it suitable for equipment overhaul and replacement. Interchange Part Numbers: 378-9517, 488-3074 Common Faults Swing slow or weak