steering tracking left and right need help!!
 

i have a 2000 blazer and out of nowhere (wasnt driving hard off road or hit anything) my steering wheel and steering will pull to the left and right and my steering wheel will feel really loose for a second then get tight again. i have checked the power steering fluid and my tie rods {inner and outer} pitman arm idler arm center link ball joints and wheel bearings and everything is solid....any ideas? and also it does get way worse at speeds over 40mph

Could be the rag joint