Hi! I've got a 2011 Chevy Silverado LT with the Z71 package. LOVE this truck, but it has an issue that is bothering me. At crawling speeds, usually with the brake very lightly pressed or going uphill with no accelerator yet the truck will begin to shake, sometimes very hard. I've unfortunately got a nice (sarcasm) commute home where I have to move at crawling speed at times due to traffic. To me it feels like a torque converter sticking or something similar. As complex as the 4x4 system is in this truck it could be something there, I would think. It's perfectly smooth/steady at a full stop and at any speed above a crawl. But I've not recieved a good answer yet as to why this is happening. I took it into my dealership with only a couple hundred miles on it and they said it was just the brakes wearing in. Later I found it that the truck also does it with no brakes, like on a slight incline where the truck will still move foward ever so slightly with no gas pressed yet. On the second trip, my advisor said it was something to do with the programming of the transmission/engine, and that he was able to reproduce it on an identical truck on the lot that had not been sold yet. And, that GM had not updated the programming for this truck yet. So I'd have to wait. Well, I got tired of waiting. And, I'm still not sold that this latest reason given is the actual problem. So I called the GM 800 number and opened case # 71-950652897. They said they would call back the next day, but I've not heard from them in the past couple of days Is this really a known problem? If so what is it? I'm getting to where I hate the drive home as I feel as if I'm in a "low-rider" bouncing down the street on pneumatic lifters. Fun if that's what you want, but I don't want this. Especially at the end of the day when I'm tired and worn out already. Please help.