New 2025 Ram 1500 Floor/Driveline vibration

[Angineer]

Hey everyone, I have a 2025 Ram 1500 with the Hurricane SO engine that has a very annoying high-speed vibration coming from the floorboard at highway speeds (73 mph and above). I’ve been trying to diagnose it since the day after I bought the truck brand new a few months ago. The dealer initially blamed the tires or balancing, but after road force balancing, rotating, and even replacing all four tires, there was no improvement. After digging deeper and attempting to diagnose it myself, I found a potential alignment issue in the truck’s driveline. By measuring the pinion gear, transfer case output shaft, and rear driveshaft angles, I discovered that the working U-joint angle is approximately 4.7–4.9 degrees, and the transfer case output flange is not parallel with the rear differential flange. My understanding is that the rear suspension on our trucks is not adjustable, so how can this be corrected? Has anyone experienced a similar issue or dealt with this kind of problem? Could this misalignment be the cause of the vibration?

 

[Drlz20]

I have the exact same issue. Did you take your findings to the dealer

 

[Hayride]

anybody? I'd like to know. the Dealer has my 2025 Ram 1500 bighorn SO to fix the vibration right now. Third time in. They replaced wheels/tire still vibration, checked front axle run out it was fine, removed drive shaft and drove with front wheels and it didn't vibrate (not a shake, more a vibrate at most all speeds mostly ~2K RPM). So they installed a new drive shaft, still vibrates. They did the sensor test with multiple sensors placed on the drivetrain and it showed left rear axle is the problem. New one is to come in today, will see if that fixes it. Had the truck 10 weeks, 4 of which have been at dealer shop due to many issues. This vibration is the biggest issue i want to drive it into a tree its Infuriating.

 

[FastBlackRam]

Sorry but if I had that kind of problem the first day of driving I would have returned it for a full refund or replacement. Seems even if they wanted to try and fix it, by this time we would be going back to day 2 and I would be returning it for a full refund or replacement vehicle.