Sorry, the NHTSA has not posted this TSB document yet.
You can still get the detailed info from Chevrolet for this TSB. Call your local Chevrolet dealer's service department & ask for a copy of TSB# PI-0491.
GM: 2006-2011 IMPALA. A CLUNK NOISE IS COMING FROM UNDER THE FRONT OF THE VEHICLE WHEN DRIVING AND/OR WHEN PUTTING THE TRANSMISSION IN DRIVE OR REVERSE. THIS MAY BE CAUSED BY DAMAGED MOUNTING AREAS. THE FRAME CAN SHIFT CAUSING THE CLUNKING NOISE. *RM
