The best choice depends on the fault, the condition of the transmission, and the overall condition of the vehicle. A localized electrical or external problem may be repairable without replacing the complete transmission.
Extensive internal wear or damage may make a larger repair or replacement more practical. Cost, parts availability, applicable warranty, and how long you intend to keep the vehicle also matter.
Certified Transmission in Bellevue can explain the available options after evaluation. Ask what each option includes and how it addresses the cause of the problem.