Every shift valve responds to a specific stress variety; so when the vehicle goes a lot quicker, the 2-to-three shift valve will consider around, since the stress within the governor is significant more than enough to trigger that valve. 1 (also labelled "L"): Restricts the transmission to 1st gear only, https://zanderrabcc.rimmablog.com/32900087/little-known-facts-about-gearbox-auto