Whurring sound, worse in 4th and 5th
 

Hey all,

On my classic I have a whurring, sloshing sound that I can hear up through the gearstick mostly when in 4th and 5th. I can make it worse feeling by pushing the stick to one side, then the vibration transfers up and I can hear it more.

Feels like a rattley bearing, doesn't really sound terminal but I would like to get it sorted. It goes away when you stop putting power through it, or push the clutch...

Any common issues that this could be?