13400-PT3-010 RR Balancer Shaft - Overview. The 13400-PT3-010 RR Balancer Shaft is an essential component in Honda marine engine systems, specifically designed for rear balancing. Its primary function is to reduce vibrations by counteracting rotational imbalances in the engine, working closely with the crankshaft. This part supports the smooth and reliable operation of the engine, helping to maintain durability and performance over time. Engineered to factory specifications, it ensures seamless