I`m going to bet that this latest TSB is for hemi 6 speed trans vehicle`s only... even though the 2014 8 speed hemi`s are doing the same thing... vibrate at 1,950 to 2,050 rpms. Every MDS hemi i`ve ever owned (and i`ve owned MANY hemi truck`s) has this harmonic vibration frequency problem. If they had done better engineering & designing of the hemi engine, (fluid dampers, silent shafts etc etc etc) it would be smoother thru any rpm & gear.
Raising the transmission shift points and/or holding out the MDS activation to eliminate the vibrations is a band-aid, it isnt a fix. My 14 hemi vibrates @ 1,950 thru 2,050 rpm`s just as bad as any other previous hemi trucks i`ve owned, just seems to be a little less due to the 8-speed, but its still there.
Why i think my 14 hemi is a little less felt is because the 8-speed is shifting thru gears so quickly, it dosent stay within the 1950/2050 rpm vibration range for very long vs the 6 speed`s... hence, less felt as often or severe, BUT, is definitely still vibrating thru the seats, floors, steering wheel, gas pedal.
I`ve learned to deal with it and live with it, i know what it is and why its doing it. I`ve fixed it on previous hemi`s, and i`ll likely fix this one too, if i dont get rid of it first. Its just alot of work involved to do it, but it can be done.