1991 740 sedan with aprox. 160,000 miles. My Volvo has become a Hummer. For past couple of months I have been hearing a humming howling kinda turbine like noise from front passenger side area. Not constantly. Comes & goes. Seems appears in morning when first use car and then goes away after being used a bit. Hear mostly when at lower speeds(say around 20 to 30 mph). Notice more when decelerating. Could this noise be front wheel bearing ?? Is this an easy repair ?? Is there a good step by step on how to do this job ?? Should I do both sides or just problem(passenger) side ?? Thanks very much.