Re: 2012 Overland shudder/vibration at cruising speeds and lurch on start.
Can you say that the shudder/vibration feels like the engine is lugging? If it goes away when you drive in "5", then it probably has something to do with the MDS system. The MDS is turned off when shift to "5" and then you are running on 8 cylinders. With MDS on, you run with 4 cylinders, and, at least on my HEMI, it feels like the engine lugs some. I find running in 5th gear is smoother, more enjoyable, although gas mileage will suffer some.