The SM 6137 Starter EGT (Epicyclic Gear Train) Gear Ring is a heavy-duty internal stationary gear component specifically engineered for the high-capacity Lucas-style (L. Type) reduction starter motors used in premium heavy commercial vehicles. This internal ring gear (also known as an annulus) provides the outer track for the planetary gears to rotate within, facilitating the massive torque multiplication required to crank the high-displacement engines found in the Tata Prima series. Precision-machined from high-density, heat-treated alloy steel, this ring is built to withstand the extreme radial pressure and mechanical stress of long-haul trucking applications.