They replaced the rear axles? Was one broken? You may have a spider gear inside the differential that has let go. To be sure, have a helper put the truck in gear with their foot on the brake while you look under the truck, if the rear driveshaft spins, then the differential is to blame.
Here is a video on how to remove the rear cover for inspection in case you need it:
Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
Saturday, May 13th, 2023 AT 10:43 AM