Design and Manufacturing of 4WD ATV Gearbox

The main objective of this project was to design and fabricate a drivetrain for an intercollegiate competition, BAJA SAE. The motivation behind undertaking this project was to gain an in-depth understanding of All-Terrain Vehicles (ATVs) and to study various parameters influencing drivetrain design and performance. Multiple configurations and design options were explored. After detailed discussions and evaluations, alternative concepts were systematically eliminated, and the most feasible option was selected. It was concluded that the transmission system would be automatic, incorporating a Continuously Variable Transmission (CVT) coupled with a two-stage gearbox, which in turn drives the half shafts for the four-wheel drive system. To ensure accurate design and efficient assembly, 3D modeling of the entire drivetrain was carried out using SolidWorks. The models were used to verify clearances, gear meshing, and alignment between components. Further, finite element analysis (FEA) was conducted to validate the strength and durability of critical parts such as gears and shafts under maximum load conditions. Following fabrication, the complete system was thoroughly tested and demonstrated excellent performance, validating the design choices, CAD modeling, and analytical predictions. The project successfully met its objective of creating a reliable, efficient, and competition-ready drivetrain for an ATV.