i stopped by my local arts store and after noticing a check engine light and their computer said "gear 5 incorrect ratio" and "gear 6 incorrect ratio how the truck is also slipping gear over 45 mph (2015 ram 2500 tr 6.4l hem

 

Got any warranty left?

 

You need to check the OD clutch pack for wear/burning friction material. The 66RFE has a tendency to leak pressure to the OD circuit when the valve body wears. Like HeyYou said, check for warranty.