gmc sierra humming underneath
I have a 2011 sierra 50,000 kms on it for the past couple of months started to notice a small hum underneath I do tow a 1000lb boat and a 2700lb trailer but not far. sometimes it hum when first started and put in reverse doesn't hum when idling also hums at 50 to 55 kms per hour when I let off the gas any help would be appreciated