The artillery weapon system muzzle disturbance is influenced largely by the carrier vibration through firing. In case of military trucks carrying cannons, the longitudinal bending vibration is the most important factor affects the muzzle disturbance. The corner stone of this article is the modal and sensitivity analysis of a chosen military truck carrying cannon in order to investigate how much the longitudinal bending natural frequencies of this truck deviated from the nominal value as a result of truck components layout or position variation and some system design parameters variations. This deviation is examined to clarify the most sensitive parameters that affect the longitudinal bending natural frequency. The dynamic characteristics of the truck, such as the natural frequencies and the mode shapes, are determined by using finite element method in order to create the truck flexible system. Via intermediate file, the flexible truck model is imported into commercial FE code “ABAQUS” software for modal analysis whose solutions agree well with an experimental data. This study shows a complete and deep investigation of the dynamic response calculations for a complex flexible military truck. In addition, the sensitivity analysis compels the designer to identify the critical variables which affect the longitudinal bending vibration beside obtain additional information about weapon system dynamics
