the steering stem on my warrior clicks when i turn the wheels from side to side.

it clicks when i hold each wheel separately with my leg as i turn the bars, so i dont think its the bearings on the ends of the tie rods. i loosened the bolts holding on the bars to the stem and the bolts holding the top part of the stem to the frame. it still clicks. i greased the bottom bearing and tightened the nut at the bottom of the stem and still, no change. any ideas?
-kev