Front wheel bearings making noise?

[dmw319]

Over a year ago I installed a front brake disc conversion along with new wheel bearings. For the past couple months I get a howling noise that sounds like its coming from the front of the car (which I am guessing is the wheel bearings). I can turn my car off compeltely while driving and the noise still remains so I don't think it is engine related (a belt, transmission noise, etc).

Can I simply take the old wheel bearings out and grease them up again? Should I have done this after a certain amount of time after installing new ones as a routine thing? I've never had to do it before but who knows. They are only $40 new from ECE, but maybe it's not the noise at all? Any advice is appreciated. Thanks yall!