So your A131L crapped out and you want a bit better of a trans. You could roll the dice with the crappy and primitive A131L or rebuild it yourself (good luck, it's not fun). Or, you swap a 4 speed in. What do you need? Not much:
A240L transmission - only used in the 1988-1992 Corollas and a few select first gen Geo Metros. Mine came from a 1989 Corolla.
Trans mount - mine came with one in good condition so I didn't bother replacing it. There's no need to change anything on the vehicle...
AE92 3 to 4 speed auto Swap: Definitive guide
A240L transmission - only used in the 1988-1992 Corollas and a few select first gen Geo Metros. Mine came from a 1989 Corolla.
Trans mount - mine came with one in good condition so I didn't bother replacing it. There's no need to change anything on the vehicle...
AE92 3 to 4 speed auto Swap: Definitive guide