I have a 2017 ram 1500 it has a vibration between1200 and 1500 rpm, the mechanic don’t seem to be able to find the reason and one says it normal, I can feel it in the wheel and the seat
Offhand I would say NO, it is not normal. Suggest you try a different dealership to investigate your problem. Even though service records are computerized, I would keep a copy of each report.
If this has the 4.7 V8, I had a friend who got Chrysler to cancel his lease on a vehicle with that engine because of a vibration the dealer could not solve. It was turning his hands numb.
I believe the 4.7 L engine retired in 2013 however there are cases where an engine is never smooth enough for the driver, there may be no solution to the complaint.
Does the vibration change when tires are rotated? Do the tires show any unusual wear patterns?
Can you generate the vibration when the vehicle is still and the trans is in neutral? How about moving in different gears?
Answers to those questions will help isolate where the vibration is coming from.
Might have something to do with the cylinder deactivation system, assuming this happens when you’re crusing and not accelerating.