Noisy DT SWISS RC760 rear wheel

[paxterg]

Whenever I put ant effort in or when riding upwards this rear wheel starts to creak and groan. There is no flex, the wheel is 3 years old, it was serviced with new cartridge bearings recently. Any suggestions?

 

[FishFright]

Is the quick release done up too tight ? It's a source of many creaking and groaning noises