Advice on Nissian sunny gearbox problem

[ChickenMob]

Hi Bros need advise on the following :

 

Friend's dad got a Sunny Ex-saloon with gearbox problem.

when driving 1/2 way sometimes the gear will be stuck at 1st gear resulting in low speed plus high RPM, need to switch off the car then

start again then it will be ok. But after driving for sometime it will persist again.

 

checked with WS they said that need to overhaul the gearbox, and they says that Sunny not able to replace the clutch as it comes in a complete

module. is it true? ( i suspect just the clutch plates need to be changed. by the way its a Auto Gear)

 

any one facing the same problem and able to advise?? thanks in advance.