The contact owns a 2018 Jeep Cherokee. The contact received notification of NHTSA Campaign Number: 25V011000 (Power Train); however, the part to do the recall repair was not yet available. The contact stated that the vehicle would roll away while parked on an incline and required that the vehicle be parked on level ground. The contact stated that the electric parking brake was inoperable. Additionally, the contact stated that while driving at various speeds, the vehicle made an abnormal humming and vibrating sound. There was no warning light illuminated. The vehicle was taken to an independent mechanic, where the contact was informed that the humming sound was coming from the transfer case. The vehicle was taken to the dealer, where it was confirmed that the failure was related to NHTSA Campaign Number: 25V011000 (Power Train). The vehicle was not repaired and was parked in the garage. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the failure and provided rental assistance for 30 days. The failure mileage was approximately 82,000. VIN tool confirms parts not available.