This work presents the design of the rear suspension and steering systems for a mobile robot intended for vineyard operations. To reduce dynamic loads on the vehicle and protect the grape crates from uneven terrain, a transverse torsion-bar suspension was designed. The system integrates seamlessly into the existing chassis, provides ±100 mm of vertical wheel travel. Analytical calculations and finite-element analysis (FEM) are used to verify stress calculations. Furthermore, a complete autonomous steering architecture was developed for reliable row navigation. This includes an outer-loop Pure Pursuit trajectory controller and an inner-loop PID. Validated with a dynamic model in Simulink, the integrated mechatronic system demonstrates trajectory tracking and safe end-of-row maneuvers, confirming its readiness for field deployment.