Clouds look full white on the bottom when using Overcast

[Max_ARG]

1. Hey guys.
   How could I get darker clouds on the bottom side when using overcast? I have tried every configuration and preset but all my overcasts look white like the sun is going through all the way. I am trying to get that darkish atmosphere on rainy days but all I get is full white iluminated overcasts. On the upper side of the overcast, darker tones are awesome, but on the bottom, everything is smooth white, like if the bottom side were ignoring all the shadows showing on the upper side. Maybe I am missing something

    
2. this is how it looks with overcast preset on the bottom https://www.facebook.com/photo/?fbid=556950505875091&set=a.556951172541691
   
   on the upper side it looks great, white and dark tones everywhere https://www.facebook.com/photo/?fbid=556950942541714&set=a.556951172541691

    
3. Graphics are on highest possible.
   Adding rain to the overcast only adds fog and the rain itself.

[NineLine]

I really think it depends on the sun position and the cloud thickness. You wont get the shadow detail on the underside of the clouds if its heavy overcast. I do see different tones on my side based on the position of the sun and amount of clouds.