Structural modal analysis is the determination of the natural frequency of vibration of physical structures and their components of mode shape, which is used in this study. This work involves static characteristics to identify the location of the high stress area and natural frequency of the chassis using modal analysis in ANSYS Workbench 15.0 and first eight modes of vibrations are extracted. Analytical modal analysis was carried out to validate the finite element models. Expected natural frequency and mode shape were validated against analytical results. Finally, the modifications of the updated Finite Element truck chassis model were proposed to reduce vibration, improve the weight, and optimize the strength of the truck chassis using American Iron and Steel Institute standards 4140/4130/4340 and AMS 6373C materials.