Yes, all of those factors can contribute to overheating. Excessive load, incorrect or degraded lubricant, restricted airflow, shaft misalignment, and worn bearings or gears are common things I’d check first.
I’d start by comparing the current operating temperature with the gearbox’s normal baseline and manufacturer specifications rather than relying on one universal temperature limit. For example, when troubleshooting a Cotta gearbox or another industrial unit, check the oil level and condition, look for leaks, and make sure the cooling system and ventilation are working properly. After that, vibration and noise checks can help identify bearing, gear, or alignment problems.
Regular infrared temperature measurements, vibration monitoring, and oil analysis are useful for spotting trends early. A gradual temperature increase is often more informative than a single reading, especially when combined with changes in noise or vibration.