This problem is slowing getting worse over the last few years. When using climate control (AC/Heater/Vent) the blower sounds like gears are stripped on level 4 (less efficient airflow and making a clicking clunking noise). More recently it began doing it on the level 3 setting. clicking sound correlates with fan speed setting.

The rear unit also clunks but in a slow ~1hz pulsing sort of way where the air surges after each clunk. Any air flow setting = same clicking rate.

Is there a way to fix this without having to buy an entire blower?

Thank you!