Sorry pilot. "Strut" is certainly the wrong term for a 400SEL with its double control arm setup, and the term has many alternate uses on this model (Camber Strut, Control Arm Strut on the rear, etc).

I meant the shock absorber.

Still think those balljoints (on the lower control arm) in particular are cheap insurance at about $40 each, considering the labor involved.
Good luck.