said by Cho Baka:Often the clutch bearing fails because the compressor has seized, and the clutch was slipping.
The clutch bearing fails more often as it turns all the time the engine is running while the compressor bearing only turns when the AC clutch is energized. That can be a 5 to 1 or 10 to 1 difference in running/turning time between the always running/turning clutch bearing and the only running/turning when AC is in use compressor bearing(s). Since the clutch bearing is always running/turning when the engine is operating, it tends to fail due to greater running/turning times.