1999 Lexus RX 300 Whining Noise

Hello
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The first thing that worries me here is the words "they don't know.". I suggest switching to a different mechanic, perhaps a transmission specialist for this issue, because if the mechanic doesn't know then they may play the "guessing game" with you and keep billing you for random repairs not really needed.

If the transmission is whining, it is usually a sign of low and/or dirty automatic transmission fluid. After you ensure that the fluid/filter are in good condition, you may point your mechanic into the direction that maybe the syncrhonizers are going bad so they can check this out.

Is the transmission slipping or acting funny in any way? Slow shifting, hard shifting etc? If not, it is probably just needing fluid.

Hope this helps.
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