Dodge 2001 Ram 1500 Owner's Manual page 1913

21 - 278 AUTOMATIC TRANSMISSION - 42RE
VALVE BODY (Continued)
SWITCH VALVE
When the transmission is in Drive Second before the
TCC application occurs (Fig. 263), the pressure regula-
tor valve is supplying torque converter pressure to the
switch valve. The switch valve directs this pressure
through the transmission input shaft, into the con-
verter, through the converter, back out between the
input shaft and the reaction shaft, and back up to the
switch valve. From the switch valve, the fluid pressure
is directed to the transmission cooler, and lubrication
pressure returns from the cooler to lubricate different
portions of the transmission.
Fig. 263 Switch Valve-Torque Converter Unlocked
Once the TCC control valve has moved to the right
(Fig. 264), line pressure is directed to the tip of the
switch valve, forcing the valve to the right. The switch
valve now vents oil from the front of the piston in the
torque converter, and supplies line pressure to the (rear)
apply side of the torque converter piston. This pressure
differential causes the piston to apply against the fric-
tion material, cutting off any further flow of line pres-
sure oil. After the switch valve is shuttled right
allowing line pressure to engage the TCC, torque con-
verter pressure is directed past the switch valve into
the transmission cooler and lubrication circuits.
BR/BE