Jeep commander vibrating/resonating @2500 RPM

Please help. I’m looking for answers…



I recently bought a certified preowned (fancy term for used) 2007 Commander limited, equiped with 5.7L Hemi. I bought it @ 30K miles, it now has around 35K. I am overall pleased with my Jeep, but routinely notice the same problem since purchase.



My commander seems quite smooth and quiet upon acceleration, until I reach @2300 RPM (regardless of gear). I then notice a “rough” feel and sound, as if the gas pedal is somewhat vibrating, or resonating. If I hold rpms at this level, the resonating does not subside. However, if I continue to accelerate, the rough feel does subside after @2700 rpm. It is once again very smooth and quiet upon further acceleration (and greater RPM). The problem only seems to occur in automatic mode between 2300 and 2700 RPM (In most gears 2nd, 3rd, 4th, and probably 5th). Other times (in lower or higher RPMs than the specified range), the engine purrs.



If I shift manually, I do not experience this problem (only in Automatic). The problem does not fluctuate with extreme temperature changes, and is not related to stagnation between drives. It is somewhat more noticeable with light throttle acceleration on an incline.



The dealership called this “normal” (with no further explanation), however it doesn’t feel “normal”.



Any ideas???



Do I need to be worried about excessive wear/damage with extra friction/vibration?



Thanks for any help





gary