front end rattle

[midwest jeep fever]

I know its hard to trouble shoot a rattle over the net but any ideas would be welcome. twice now I have had a terrible rattle that sounds like its right below the front end of my jeep. it only happened twice with a long time inbetween episodes. it seemed to be worse when I hit smaller bumps close together. I jacked up the front and checked for play in the wheel bearings, tugged and yanked on all suspension parts and nada everything is tight. the only thing with any play at all is the front drive shaft and it is very minimal not enough to create the racket I was hearing. any suggestions on what to check???