Front thrust arm and control arm bushings can crack and sometimes tear completely. If this is not repaired quickly, damage to the front subframe unit will occur, which is very expensive to repair. Updated control arms (that prevent damage to the subframe when the bushings wear out) are available.Google+
Car Problem Reports
Mercedes-Benz S430 Front Thrust Arm and Control Arm Bushing Can Crack or Tear
Mercedes-Benz S430 Problem
Average Mileage: 135,000 mi (81,000 mi - 189,000 mi)
I have a loosening to the front thrust arm, passenger front tire. I just had my tires replaced and noticed vibration at high speeds.
Visitor, 2004 Mercedes-Benz S430, 81,000 mi
had to replace lower drivers side control arm due to busted ball joints $750