A 5-speed synchronized manual transmission is available for all models. Only one gearbox is offered for each family; there are no optional ratios or gear arrangements. The transaxle number stamped on the case indicates the family and running serial number for the transaxle. In general, transaxles are not interchangeable between model families.
Transaxles are selected by the manufacturer to fit the engine performance characteristics of the car with consideration to other variables such as area of sale, emission class, vehicle loading, brakes, etc. Even if a replacement unit physically fit into a dissimilar car, the performance of the transaxle would be a poor match to the present engine; driveability, fuel economy and emissions would suffer.
If you're considering replacing the transaxle rather than repairing a failure, stick to the same transaxle group; i.e., if the old unit's trans number was YS1, then that is also what the replacement unit must be. Transaxle identification numbers begin with the following groups: