I sure like how Cummins has quieted down the engine compared to prior years.
This may be just me.., but on all my new vehicles I changed the engine oil & filter after the first 500 miles just to flush out any unwanted particles from the initial break-in, and/or the manufacturing process.
Also, check the rear axle differential fluid (and front if 4x4) as well. My rear axle fluid was dirty at 500 miles and had it changed as well. The front axle fluid was fine, but I changed it anyways.
I've spent a lot of time over the years in automotive drive train plants (engine, transmission, axle, etc.) and found anytime there is metal cutting (gears, etc.) going on there is always the potential of some metal chips getting carried into final assembly (axles and ring gears were the worst offenders).
Just food for thought.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V