I have a 2006 h2 luxury ed. My service 4wd light comes on periodically and have also had a whirring sound from the area of the front axles for a while as well as it was difficult to turn. I recently had the power steering pump, belts and water pump replaced and the steering issue is resolved but the whirring sound is still there and the light comes on more frequently.

 

From what your describing it sounds like your 4x4 system is trying to engage. Your switch may be faulty.
I know mine is not even engaging. My switch or actuator is out.
Good luck..

 

Thank you, I will look into that. Was concerned could be the transfer case or transfer case motor or rack and pinion