The Office of Defects Investigation (ODI) received a consumer complaint from an ambulance fleet describing that while driving at highway speeds, the driver and assistant felt a vibration and heard a loud noise. Following these events, the engine shut off resulting in a loss of motive power, steering assist and service brakes. The driver was able control the vehicle and bring it to the shoulder of the road. It was determined that the transfer case had broken apart. During a shop inspection, damage was found to fuel lines, brake lines, floor board and the front driveshaft (broken off).When contacted, the complaining fleet provided information on 2 additional ambulance fleets experiencing similar scenarios. In one case, the ambulance was transporting a patient when the incident occurred. The truck was not able to exit onto the shoulder and was stalled on the main roadway. From Quarter 4, 2018 Early Warning Reporting data submitted by FCA, ODI identified failures similar to those described by the ambulance fleets. One failure resulted in a loss of motive power and airbag deployments. An interview with the owner of the company indicated the truck had been serviced exclusively by an authorized Chrysler dealer.Consequences of, and systems impacted by driveshaft and/or transfer case failures include the loss of engine power, loss of steering assist, loss of foundation brakes, unintended air bag deployment and engine/cab fires from combustible fluids striking hot exhaust. ODI is opening this Preliminary Evaluation (PE) to further evaluate the frequency and severity of the alleged defect.The above VOQs can be reviewed at NHTSA.gov under identification numbers 11113352, 11121408 and 11104270.