The SM 4657 is a heavy-duty Starter Drive (Self Drive) designed for a specific range of diesel passenger and utility vehicles. While often referenced for Tata Indigo diesel variants, it is also utilized in specific Mahindra light commercial applications. This unit features a high-density 12-tooth pinion—uncommon for standard passenger cars—providing the increased gear reduction and torque necessary to turn over high-compression diesel engines in cold-start conditions.
