I take my 2015 Sport 4x2 in next friday for the same issue.. vibrates and shakes something crazy around 60-80mph..
I had a 2014 4x2 pentastar v6 that did not have the issue.. hope it's just getting the wheels balanced but from reading here it prob won't be. If my v6 didn't do this but the v8 does.. what's different? I know the drive shafts are.
Thats the first thing I noticed on my way home when I bought my 4x2 a couple months ago. Started floorpan vibration and felt in floor and back of seats. Not on steering wheel . Occured approx at 55-65. After a while its gone now or least much less noticable. Mileage now is 1700 miles.
Scale of 10 now, I feel it at about 3 less noticable. Then again, perhaps its the road as when driving on the same road wifes Mazda CX 5 does make similar shake but her suspension is more advanced and takes it better than the live axle on the ram.
Prior it shook worse, I could see the passanger front seat back rest shaking whilst it occured.
PS. I would never trust a dealers mechanic to balance or load balance my tires in respect of ruling this issue in or out . Remember the lowest paid person at the dealership will be doing this task under time frames.
Just do the basic simple stuff, ask the dealership to allow you to test drive another Ram, get the other ram to speed where your vibration occurs . Then take the ram back and take the wheels and put them on your truck. If vibration still persists then you can be 100% certain its not wheel or tire related. This is the only way to start the process. Screw someones take that they have balanced your current wheels LOL.
