Valves & Hydraulic Control Units

Pressure Regulator
Regulates line pressure according to pump speed and engine torque.

Manual Valve
Establishes the range of transmission operation as selected through the manual lever.

Governor Assembly
Generates a speed sensitive oil pressure that increases with output shaft or vehicle speed. Governor pressure is used to control the shift points and modulator pressure regulation.

Vacuum Modulator Valve
Provides a pressure signal to the pressure regulator which controls line pressure automatically. Modulator pressure varies in the same manner as torque input to the transmission and is regulated by engine vacuum. It is decreased by governor pressure with an increase in vehicle speed.

1-2 Shift Valve
Routes oil pressure that causes the transmission to shift from 1-2 or 2-1. Its operation is controlled by governor pressure, detent pressure, modulator pressure and spring force.

1-2 Accumulator
Regulates oil pressure to cushion application of the intermediate clutch.

2-3 Accumulator
Regulates oil pressure to cushion the application of the direct clutch.

2-3 Shift Valve
Routes oil pressure that causes the transmission to shift from 2-3 or 3-2. Its operation is controlled by modulator, governor, detent and modulator valves pressures as well as a spring force.

Detent Valve
Actuated by cable linkage from throttle linkage, directs regulated modulator pressure tending to hold the 1-2 shift and 2-3 shift valves in the downshift position and provides areas for modulator and detent regulated pressures for detent 2-1, 3-1 and 3-2 downshifts.

Detent Regulator Valve
Regulates line pressure into detent regulator oil which is used to control the car speed at which the 1-2 and 2-3 upshifts occur.

Oil Pump Priming Valve
Provides an exhaust for any air that may be trapped in the pump and suction oil passages.

Cooler Bypass Valve
Permits oil to be fed directly from the converter to the lubrication circuit when the oil is cold or the cooler or the cooler lines become restricted.

Manual Low Control Valve
Protects the engine by preventing low range engagement at car speeds over 50 mph.