Dodge Ram Truck 1500-2500-3500. Manual — part 1807

This exposes a larger passage into the piston retainer
resulting in a much faster clutch fill and apply
sequence. The quick fill valve does not bypass the
regular clutch feed orifice throughout the 3-4 upshift.
Instead, once a predetermined pressure develops
within the clutch, the valve closes the bypass. Clutch
fill is then completed through the regular feed orifice.

THROTTLE VALVE

In all gear positions the throttle valve is being supplied with line pressure. The throttle valve meters and reduces the
line pressure that now becomes throttle pressure. The throttle valve is moved by a spring and the kickdown valve,

3-4 Shift Valve After Shift

Throttle Valve

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which is mechanically connected to the throttle. The larger the throttle opening, the higher the throttle pressure (to
a maximum of line pressure). The smaller the throttle opening, the lower the throttle pressure (to a minimum of zero
at idle). As engine speed increases, the increase in pump speed increases pump output. The increase in pressure
and volume must be regulated to maintain the balance within the transmission. To do this, throttle pressure is routed
to the reaction area on the right side of the throttle pressure plug (in the regulator valve).

The higher engine speed and line pressure would open the vent too far and reduce line pressure too much. Throttle
pressure, which increases with engine speed (throttle opening), is used to oppose the movement of the pressure
valve to help control the metering passage at the vent. The throttle pressure is combined with spring pressure to
reduce the force of the throttle pressure plug on the pressure valve. The larger spring at the right closes the reg-
ulator valve passage and maintains or increases line pressure. The increased line pressure works against the reac-
tion area of the line pressure plug and the 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 kick-
down 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.

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SWITCH VALVE

When the transmission is in Drive Second before the TCC application occurs, the pressure regulator valve is sup-
plying 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.

Switch Valve - Torque Converter Unlocked

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MANUAL VALVE

The manual valve is a relay valve. The purpose of the manual valve is to direct fluid to the correct circuit needed
for a specific gear or driving range. The manual valve, as the name implies, is manually operated by the driver with
a lever located on the side of the valve body. The valve is connected mechanically by either a cable or linkage to
the gearshift mechanism. The valve is held in each of its positions by a spring-loaded roller or ball that engages the
“roostercomb” of the manual valve lever.

Switch Valve - Torque Converter Locked

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