2018 2500 5.7 Engine 6 speed auto 38K on the clock No check engine lights or any other warnings indicated I noticed the issue a couple of months back on a return trip from Tn not towing or any load in the vehicle . Driving on an incline 70-75 mps pushing on the accelerator and putting load on the engine it had a slight vibration but wasn't consistent . Figured maybe it was something on the road causing the vibration and didnt think much of it . Flash forward to today , Past few weeks I have been paying attention to the tach . Ive noticed while accelerating lightly as the tach approaches 2K needle with fluctuate (bouncing maybe 200 rpms up and down) and I can feel that slight vibration again . Oddly enough if I give put more throttle into it , the vibration and the needle fluctuations will disappear and will accelerate normally with no issues . If I take off medium or full throttle acceleration no issues . Truck pulls strong and doesnt hesitate or anything that would indicate any issues . Tires recently balanced and rotated serviced regularly . Any thoughts or ideas ?