Help!

I have a rattle/bump in my front end and have no idea where it is coming from.

It sounds like a loose shock, ya know when someone forgot to tighten the mounting bolts.
When driving over an uneven spot in the road I can actually feel a slight tap or bump in my feet, especially on the dead pedal. WTF!
I have checked the following (even used my fancy mirror on stick):
sway bar bracket torque
lubed the bushings
end link bolts for tightness
shocks top and bottom
upper and lower a-arm attach points
I looked at the top of the transverse leaf spring, using a mirror cuz my head ain't that small!
Is there supposed to be a nut on the vertical threaded bolt that sticks through the spring at each end?
Sounds like a silly question but I'm not familiar with the mount and can not get a really good look.
Any and all suggestions are entertained.










