Look for anything loose by pulling, twisting and prying on joints (tie rods, ball joints) etc.

I am not overly familiar with W211's...on W124's the ball joints must be oriented with the notch facing inward. Can someone on the forum please advise if this applies for W211's?

If the control arms were replaced especially if only one, they may not have tightened it with weight on the arms and possibly never aligned it well.

Look at the steering rack bushings for wear and proper tightening. Does it look like the rack was replaced?

Look closely for a bent spindle, they are often overlooked.

Good luck!!!

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