I know most of you guys hate it when a member posts without researching the forum. I looked over many posts but was unable to find something exactly like my problem. I have a Black 2005 Lariat Screw with about 1200 miles on it. Lately whenever I stop at a red light or a stop sign, i feel a ...rattle, vibration, shaking type noise eminating from the front quarter of the truck. I checked under the dash but my aftermarket alarm is snug in place and the noise doesn't appear to come from under the dash.... Funny thing is, at a red light or stop sign when I put the truck in park or neutral the noise stops. As soon as I put it back in Drive it resumes....with a sort of howl from the rear like the transmission gearing up to do...something...

Guys, I"m at my wits end....any ideas....

 

There's a revised PCM calibration for trucks that idle rough, yours may fall under that. Kinda makes me think that's what you're feeling, since it's not present in park or neutral. All this calibration does is increase idle speed slightly, the same as if it were in park or neutral.