Transmission Shudder problems of the 2015 GMC Sierra

The contact owns a 2015 GMC Sierra. The contact stated that while driving at various speeds, the transmission vibrated causing a hesitation when the gears shifted. The contact mentioned that the failure was most severe while driving at speeds between 40-50 mph. The vehicle was taken to a dealer who changed the gear ratio and adjusted the rear end. The vehicle was repaired, but the failure recurred. The manufacturer was notified of the failure. The failure mileage was 250.