<p>This study conducts a comprehensive analysis of the strain characteristics exhibited by spur gears fabricated from High-Density Polyethylene (HDPE) and HDPE enhanced with a dual nanofiller system comprising titanium dioxide (TiO₂) and silicon dioxide (SiO₂). The spur gears were manufactured through high-precision injection molding and tested on a specially developed gear testing apparatus, which incorporated a carbon slip ring and an Arduino-based system for real-time strain monitoring. Finite Element Analysis (FEA) was performed in ANSYS Workbench to simulate real-world gear misalignments, including radial, axial, and yaw deviations. The computational strain results were validated through experimental testing to ensure the accuracy of the simulations. Findings reveal that incorporating TiO₂ and SiO₂ nanoparticles into the HDPE matrix significantly enhances strain resistance by increasing material stiffness, reducing localized deformations, and promoting more uniform stress distribution. The reinforced gears exhibited a notable reduction in strain, ranging from 10 to 35% compared to unfilled HDPE gears, depending on the type and magnitude of misalignment. These improvements highlight the potential of hybrid nanofiller-reinforced HDPE gears as a high-performance alternative for applications involving complex or imperfect alignment conditions, offering superior mechanical durability and material efficiency.</p> Graphical abstract <p></p>