I only speak from doing ball joints and tie rods on my C-class.

But did you tighten up all the bolts with the tires suspended off the ground? I am thinking that may be the problem. I found that having the tires/suspension loaded with the cars weight allowed me to tighten up difficult bolts with greater ease.

Also when you drive the car is the steering way more accurate than before.

I know I didn't answer your ? but though it may be a good tip.