i know exactly what the problem is. I just had the same problem for months and i couldnt figuer it out. Take your springs off and ill bet you $500 that your spring perch centering holes arent round anymore(and i bet its your passanger side to). My center holes were ripped all to hell from poor u-bolts that loosened off . All i did was get two peaces of flat bar and drilled the center holes out and welded them to the top of your spring perches.
Good luck and hope thats your problem
