Sc 300 Makes Growling Noise Upon Startup Ac Or Power Steering?

[SC for Life]

Great day fellow Lexus companions! Just bought my 7th SC since 1995. Just could not stay away. Upon startup when I turn on the ac I can hear a brief growling or deep drone sound it is on for a few seconds and then goes away....not sure if it is ac or power steering. When I put my hand on the power steering pump in does seem like it is grinding some but fluids are clean and full. If it is the ac can just the ac compressor bearing be changed without pulling the compressor off? Any suggestions is it may be ac or power steering?