My opinion.... A few weeks ago I heard a loud BOOM as though a bomb went off and the rear Air Conditioner started some serious vibration, I quickly killed it, and later went topside and confirmed what happened.. The condenser fan had "Blown Up" (All but one blade flew off)
I then called around to find a replacement and found out.. .IT WAS A CHINA BOMB.
Got a US made fan that was exactly the same size, pitch, number of blades, etc and put it on.
So China Bombs are not just tires.
(OH, My AC troubles did not stop there.. ON the other (American made) A/C the blanged blower motor sized up this week.... Thankfully i had a spare (Actually the original motor in that unit was being carried as a spare, long story there that I do not care to type just now).