2005 Dodge Caravan steering problem

I have been trying to fix a knock which also feels to have some play in the front end of a 2005 Dodge Caravan when you drive on rough roads for example driving over pot holes, even when driving slowly I can feel the knock very clearly. I replaced the sway bar bushings and a outer tie rod end which was definitely worn and was causing noises which did go away when they were replaced but I can still feel a knock coming somewhere from the front end. I checked the ball joints and control arm bushings by wedging a steel pry bar between them and trying to see or feel some play but could not feel any, I also checked the sway bar end links by holding them tight in my hand and tried to shake them back and forth and could not feel any play in them either. I noticed some play in the rack and pinion when I tried to move the tire back and forth like when you check to see if the tie rod ends are bad. I was wondering if the rack and pinion can cause a knock that can be so noticeable or am I looking in the wrong direction.