Squeaky Suspension on a 1999 Explorer

I bought a 99 explorer used a year ago. It runs great, no problems, but the suspension squeaks constantly. I've tried to lube it up with spray lubricant, but that does not see to do much. As I drive down the street with the windows down, all I can hear is the squeaking. It seems to be louder in the front as I hit bumps or pot holes.

Is there anytihing I can do to reduce the squeaking? Can I try to press grease into the tortion bar connections? Where else can I but lubricant to quiet down the suspention. Spray lube like WD40 doesn't seem to be good enough.

Suggestiions?

Thanks,

Bob