Reverse gear getting locked up

Cvzg77r

Im getting a transmission replaced later this week should they replace that by instructions of the service manual or is that something i would have to ask for extra?? i only have 9k miles i doubt they'll actually replace it unless nissan states somewhere that it must be replaced they were trying to say my trans was fine until i went up their and test drove my car with the tech and even then i was having a hard time he kept saying its fine its fine....