1ST + R Lock-Up Valve

Valves are illustrated in their positions when the selector lever is set to neutral.

This valve has 3 functions:
- It prevents shifting into reverse above a certain speed and blocks the fluid supply to clutch B and brake D. Valve function is controlled by governor pressure and system pressure.
- In position 1, the valve prevents up shift to 2nd by leading system pressure to shift valve 1-2, which is thus blocked in 1st position.
- When manually downshifting from 2nd to 1st, the valve prevents downshift to 1st above a certain speed by blocking system pressure to brake D.