While replacing the serpentine belt and tensioner in my 91 300SE, I noticed that the viscous fan bearing and the idler pulley next to it need replacement. Is replacing these items as straightforward as the CD manual suggests? Actually, there's no detailed procedure for just these parts. Is there a gasket between the timing chain cover and the part that contains the fan bearing?

Thanks,
Sixto
78 450SEL
91 300SE