Hello, I have a 2001 2dr 4wd Blazer, I am getting a humming noise during left turns and sometimes while driving straight. The noise goes away when turning right or if I select 4hi. Comes back when I select 2wd. The humming also increases in speed with the vehicle. Read a bunch of posts and believed it would be the right hub assy. Changed it but noise is still there. Any ideas? Thanks