Whirring front diff.
 

My front diff whirrs on throttle and is quiet off throttle. What is best route to take ? Replace the box or remove the box and change the diff bearings ? The gearbox itself is smooth with good changes. Is there anyone on here who repairs impreza boxes ? Car has 104k miles blobeye WRX.

You have an open front diff

Before you do that, Check the diff preload. These have been known to come loose. Change the oil.

Else replace carrier bearings. OEM subaru is expensive, but NTk or Timken is reasonably priced.

I have mic'ed the timken ones. They are perfect.