.020 is normal they all have some movement up and down even if it's brand new. Adjusting the sector gear preload is to tighten gear mesh and on center feel. Making it to tight will make it misserable to drive. Do you have alot of steering wheel play? If so check the track bar. Is the noise you are hearing over bumps? If so with the truck on the ground rock the truck side to side and check the front sway bar links. The ball socket ends go bad quite frequently.