Have a 2008 Ram 3500 dually w/6.7 Cummins. Transmission feels like it is trying to shift, sort of stutters. No codes. My mechanic took a ride with me and while driving his computer shows current gear 6th, desired gear 5th. Desired is always one lower than gear you are in. At low speed, 20-30, when you let off the accelerator it really shudders. Dealer says no code, no issue. Some days it feels like the tranny is going to fall out the bottom of the truck. Any thoughts.

 

Welcome to DF!

Have you tried to manually shift the gears down, it sounds like its not wanting to downshift on its own.

 

When you downshift, computer shows current gear 5th, desired gear 4th and so on down the line. Yesterday traveling at approx 30 mph approaching an intersection let off the throttle to slow down, truck shuddered so hard I would have thought tranny had fallen out.