RAM 3500 HD Truck 2WD L6-6.7L DSL Turbo (2008)
reaction area left of land #3 simultaneously moves the regulator valve train to the right and controls the metering passage.
The kickdown valve, along with the throttle valve, serve to delay upshifts until the correct vehicle speed has been reached. It also controls downshifts
upon driver demand, or increased engine load. If these valves were not in place, the shift points would be at the same speed for all throttle positions. The
kickdown valve is actuated by a cam connected to the throttle. This is accomplished through either a linkage or a cable. The cam forces the kickdown
valve toward the throttle valve compressing the spring between them and moving the throttle valve. As the throttle valve land starts to uncover its port,
line pressure is "metered" out into the circuits and viewed as throttle pressure. This increased throttle pressure is metered out into the circuits it is applied
to: the 1-2 and 2-3 shift valves. When the throttle pressure is high enough, a 3-2 downshift will occur. If the vehicle speed is low enough, a 2-1 downshift
will occur.
SWITCH VALVE
Switch Valve - Torque Converter Unlocked
When the transmission is in Drive Second before the TCC application occurs, the pressure regulator valve is supplying torque converter pressure to the
switch valve. The switch valve directs this pressure through the transmission input shaft, into the converter, 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.
