The SM 6154 Starter EGT (Epicyclic Gear Train) Rubber Set is an industrial-grade internal dampening kit specifically engineered for high-torque Bosch-style (B. Type) reduction starter motors. These heavy-duty rubbers are positioned within the planetary gear carrier to provide critical shock absorption during the high-compression cranking cycles of earthmoving machinery and heavy-duty truck engines. Designed for the extreme mechanical stress of the JCB 3DX and Hino powertrains, these dampers prevent gear-tooth shearing and internal housing damage by neutralizing sudden rotational impacts.