I have a 2002 C230 coupe with an automatic transmission, it recently developed a whine in second and drive, the noise goes away in the other gears and when in overdrive. i think its the planetary gears since i had one transmission to fail already because of the planetary gears. My car has only 21,659 miles. should i have the planetary gears replaced before they get any worse, or should i put something like Lubegard in it and hope for the best?