This study takes a close look at the geometric design, modeling, and physical analysis of a pair of bevel gears with spiral teeth. The focus is on a single project. It started with a close look at a spiral bevel gear taken from the differential box of a Polski Fiat. Using design software, perfectly designed the gear. Keeping the original parameters from the Polski Fiat gear was key. Paid a ton of attention to this, so the modeling process was accurate and trustworthy. This laid a solid groundwork for the physical analysis which was done afterwards. Crucial to the study was making four distinct gear designs, each with a unique helix angle (25°,30°,35°& 40°). This method made a deep side-by-side comparison possible, looking closely at how changes in the helix angle influence the gear's functionality under simulated scenarios. Ansys was used for static structural analysis, and each model faced a variety of trials with differing moment loads. The emphasis was on important measures like total deformation, directional deformation, equivalent stress, and normal stress. This study's results gave useful understanding about how each gear type behaves under various situations. It uncovered important information on how helix angles impact and how well the gear works. Especially looking at how stress is spread around the gear and how the gear changes shape. These findings were correct and could be used accurately by comparing them to theory and well-known gear standards