2nd Gen Non-Engine/Transmission thumping noise in front end

[robertsalverda]

hi guys, i'm wondering if anyone can help me out here. i'm getting a thumping noise that my wife can actually feel in the floorboards whenever i take a fairly sharp turn at any speed. sometimes it happens even when we are driving on a straight rough road. i took it to a friend at a garage and he replaced the upper and lower ball joints. although the problem doesn't seem to sound as loud, it is still there. my friend says the shocks look okay and everything seems to feel tight. any ideas? it is a 98 one ton dually, 2wd. any thoughts or ideas would be greatly appreciated. thanx