I have a MY06 WRX and I do a lot of long distance trips from Dunsborough to Perth @ speed i.e 130kmh.

After about and hour or so the gearbox or diff starts to makes a whining noise when you let of the throttle or slow down, even down at about 60kmh!!

Is this the gear box / diff oil getting too hot or do I need a thicker oil???
I am not a tec head so any ideas.

The car is going to MMS tomorrow so I can get is sorted if I know whats wrong..

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