Shift Timing Control

Operation of 3-2 timing valve
- When governor pressure is low at low vehicle speeds, the 3-2 timing valve is held at the right position and oil passage (1) is opened to oil passages (2) and (3).
- When shifts are made from 3rd to 2nd gear with the 3-2 timing valve held in that position, the band servo 3rd "release" pressure flows through passages (2) and (3) and is drained quickly.
- The 3-2 timing valve is held at the left position by governor pressure at high vehicle speeds. Oil passage (1) is then opened to oil passage (2), and oil passage (3) is closed. The band servo 3rd "release" pressure is drained via oil passage (2) more slowly than at low vehicle speeds.
- Engine speed increases quickly while shifting from 3rd to 2nd gear at low vehicle speeds. Engine speed increases slowly at high vehicle speeds. For this reason, the 3-2 timing valve changes the drain speed of the band servo 3rd "release" pressure to accommodate engine speed during high vehicle speeds.