Objective <p>This study aims to investigate the influence of temperature rise on scuffing failure in aviation spiral bevel gears by proposing a thermal dynamic transmission error (TDTE) metric and analyzing the associated thermo-mechanical dynamics.</p> Methods <p>A thermo-mechanical dynamic coupling model was developed to obtain temperature distributions under actual operating conditions. A dynamic model incorporating temperature-dependent mesh stiffness was established, and experimental tests were conducted on a dedicated rig to measure temperature rise under varying rotational speeds and scuffing conditions. Additionally, a finite element model (FEM) with direct heat source loading on the gear body was constructed. Model accuracy was validated against experimental data.</p> Results <p>The maximum deviation between experimental and FEM results was 7.9%, indicating higher predictive accuracy compared to conventional thermo-elastohydrodynamic&#xa0;(TEHD) models. After scuffing, transmission error increased by 27.66% between maximum and minimum rotational speeds, while time-varying&#xa0;mesh stiffness decreased by 31.21%. Variance in vibration amplitude rose with temperature increase: at 20 N·m, values were 3.60, 4.40, and 4.47 m/s²; at 100&#xa0;N·m, they reached 4.67, 4.84, and 4.88 m/s². Higher tooth surface temperature amplified vibration amplitude and reduced natural frequency.</p> Conclusion <p>Temperature-induced reduction in mesh stiffness exacerbates transmission error and vibration severity, constituting a primary mechanism for scuffing-related gear failure. The proposed TDTE metric and modeling approach provide an effective means to quantify and predict thermal effects in gear systems.</p>