The aforementioned friction bands and clutches are managed applying automatic transmission fluid (ATF), which can be pressurized by a pump and after that directed to the appropriate bands/clutches to obtain the essential gear ratio. one (also labelled "L"): Restricts the transmission to 1st equipment only, also called a "lower gear". https://gearboxauto08516.suomiblog.com/not-known-factual-statements-about-gearbox-auto-49364979