I have a 2012 Ram 1500 4x4 Express Regular cab. I have this odd transmission noise and vibration. In looking around at the various forums I come across reference to star case S1121000005, which describes fairly closely what I'm experiencing. But from what I read it applies to 2009-2011 5 spd transmissions where my 2012 has a 6 spd.

The only difference is that in my truck it starts at around 1250 rpm and goes up to 1700 rpm. It doesn't do it when I have Tow\Haul mode engaged. Occasionally the transmission acts like it is trying to shift and it get's a load growling noise and a fair amount of vibration. I want to take it to the dealer to have it looked at but would like to have information to discuss with them in case they try to tell me it's normal.