Not sure what the problem is. 2012 Stock 3500 SRW Auto. When its cold out I start my pickup for it to warm up. When I leave for work it sometimes lurches, in forward or reverse, depending on which way I leave. Once on the road, at slow speeds, when I let off the throttle it's as if the engine or transmission starts shuddering. Once I accelerate again it stops. It will do this for about 1 to 2 miles. After that it goes away until the engine is cold again. Only does it after it has been shut down over nigh or all day in cold weather. I have warmed it up with the transmission in neutral and it made zero difference.