Funny noise when dropping down the gears(whining rubbing)

[Knight Rider S4]

Just noticed it today when i am coming down the gears at speed there is not a very healthy noise coming from the gearbox area whining sort of

The clutch seems fine and the box is working ok going up the gears

My thoughts are at the moment before i go into it................

Gearbox mounts?,,,movement causing rubbing and vibration

Check gear oil


Any other ideas would be appreciated

Cheers