CHEVROLET/GMC: THE ENGINE, WHILE DRIVING UP AN INCLINE, WITH A LOAD, AT 1350 RPM, WOULD EXPERIENCE AN EXHAUST RESONANCE VIBRATION, OR DRONING OR BUZZING TYPE NOISE, IN A HIGHER GEAR UNDER A LOAD CAUSING PULSING/FIRING THROUGH DRIVELINE. MODELS 2011 SILVERADO 2500/3500 HD; SIERRA 2500/3500 HD. *PE
