Some 2011-2013 Ford Focus vehicles may exhibit an excessive engine vibration at idle, most noticed when the transmission is engaged in reverse. This condition is caused by small stones or other road debris packed into the rear engine roll restrictor.
Inspect the roll restrictor and remove any debris (dirt, snow, stones, etc.).
Remove the cross member-to-roll restrictor mounting bolt and install the service shield (P/N 2M5Z-16102-AB).
Install the mounting bolt and torque (2000-2007 model year: 35 ft.-lbs.; 2008-2011 models: 52 ft.-lbs.).