DODGE RAM 2002 Service Repair Manual

The valve is serviced as an assembly; it is not
repairable. Do not clean the valve if restricted, or
contaminated by sludge, or debris. If the valve fails,
or if a transmission malfunction occurs that gener-
ates significant amounts of sludge and/or clutch par-
ticles and metal shavings, the valve must be
replaced.
The valve must be removed whenever the cooler
and lines are reverse flushed. The valve can be flow
tested when necessary. The procedure is exactly the
same as for flow testing a cooler.
If the valve is restricted, installed backwards, or in
the wrong line, it will cause an overheating condition
and possible transmission failure.
CAUTION: The drainback valve is a one-way flow
device. It must be properly oriented in terms of flow
direction for the cooler to function properly. The
valve must be installed in the pressure line. Other-
wise flow will be blocked and would cause an over-
heating condition and eventual transmission failure.
TRANSMISSION
TEMPERATURE SENSOR
DESCRIPTION
Transmission fluid temperature readings are sup-
plied to the transmission control module by the ther-
mistor (Fig. 246). The temperature readings are used
to control engagement of the fourth gear overdrive
clutch, the converter clutch, and governor pressure.
Normal resistance value for the thermistor at room
temperature is approximately 2000 ohms.
The thermistor is part of the governor pressure
sensor assembly and is immersed in transmission
fluid at all times.
OPERATION
The PCM prevents engagement of the converter
clutch and overdrive clutch, when fluid temperature
is below approximately 10ÉC (50ÉF).
If fluid temperature exceeds 126ÉC (260ÉF), the
PCM causes a 4-3 downshift and engage the con-
verter clutch. Engagement is according to the third
gear converter clutch engagement schedule.
The overdrive OFF lamp in the instrument panel
illuminates when the shift back to third occurs. The
transmission will not allow fourth gear operation
until fluid temperature decreases to approximately
110ÉC (230ÉF).
VALVE BODY
DESCRIPTION
The valve body consists of a cast aluminum valve
body, a separator plate, and transfer plate. The valve
body contains valves and check balls that control
fluid delivery to the torque converter clutch, bands,
and frictional clutches. The valve body contains the
following components (Fig. 247), (Fig. 248), (Fig.
249), and (Fig. 250):
²Regulator valve
²Regulator valve throttle pressure plug
²Line pressure plug and sleeve
²Kickdown valve
²Kickdown limit valve
²1-2 shift valve
²1-2 control valve
²2-3 shift valve
²2-3 governor plug
²3-4 shift valve
²3-4 timing valve
²3-4 quick fill valve
²3-4 accumulator
²Throttle valve
²Throttle pressure plug
²Switch valve
²Manual valve
²Converter clutch lock-up valve
²Converter clutch lock-up timing Valve
²Shuttle valve
²Shuttle valve throttle plug
²Boost Valve
²10 check balls
By adjusting the spring pressure acting on the reg-
ulator valve, transmission line pressure can be
adjusted.
Fig. 246 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
21 - 218 AUTOMATIC TRANSMISSION - 46REBR/BE
TORQUE CONVERTER DRAINBACK VALVE (Continued)

Fig. 247 Upper Housing Control Valve Locations
1 - UPPER HOUSING 8 - MANUAL VALVE
2 - REGULATOR VALVE 9 - 1-2 GOVERNOR PLUG
3 - SWITCH VALVE 10 - GOVERNOR PLUG COVER
4 - REGULATOR VALVE SPRING 11 - THROTTLE PLUG
5 - KICKDOWN VALVE 12 - 2-3 GOVERNOR PLUG
6 - KICKDOWN DETENT 13 - SHUTTLE VALVE PRIMARY SPRING
7 - THROTTLE VALVE AND SPRING
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 219
VALVE BODY (Continued)

Fig. 248 Shuttle and Boost Valve Locations
1 - SPRING 8 - SHUTTLE VALVE COVER
2 - RETAINER 9 - SHUTTLE VALVE
3 - BOOST VALVE 10 - SHUTTLE VALVE PRIMARY SPRING
4 - BOOST VALVE PLUG 11 - GOVERNOR PLUG COVER
5 - SPRING GUIDES 12 - THROTTLE PLUG
6 - E-CLIP 13 - UPPER HOUSING
7 - SHUTTLE VALVE SECONDARY SPRING 14 - BOOST VALVE COVER
21 - 220 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

Fig. 249 Upper Housing Shift Valve and Pressure Plug Locations
1 - UPPER HOUSING 8 - RETAINER
2 - 1-2 SHIFT VALVE AND SPRING 9 - 1-2 SHIFT CONTROL VALVE AND SPRING
3 - 2-3 SHIFT VALVE AND SPRING 10 - PRESSURE PLUG COVER
4 - 2-3 THROTTLE PLUG 11 - LINE PRESSURE PLUG
5 - LIMIT VALVE HOUSING 12 - PLUG SLEEVE
6 - LIMIT VALVE COVER 13 - THROTTLE PRESSURE SPRING AND PLUG
7 - LIMIT VALVE AND SPRING
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 221
VALVE BODY (Continued)

Fig. 250 Lower Housing Shift Valves and Springs
1 - 3-4 ACCUMULATOR HOUSING 11 - TIMING VALVE COVER
2 - 3-4 SHIFT VALVE AND SPRING 12 - PLUG
3 - PLUG 13 - 3-4 TIMING VALVE AND SPRING
4 - SPRING RETAINER 14 - LOWER HOUSING
5 - CONVERTER CLUTCH VALVE AND SPRING 15 - ACCUMULATOR END PLATE
6 - CONVERTER CLUTCH TIMING VALVE AND SPRING 16 - 3-4 ACCUMULATOR PISTON AND SPRING
7 - OVERDRIVE SEPARATOR PLATE 17 - E-CLIP
8 - CASE CONNECTOR 18 - 3-4 QUICK FILL SPRING AND VALVE
9 - CONVERTER CLUTCH SOLENOID 19 - SOLENOID GASKET
10 - OVERDRIVE SOLENOID 20 - HARNESS
21 - 222 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
CHECK BALLS
CHECK BALL NUMBER DESCRIPTION
1 Allows either the manual valve to put line pressure on the 1-2 governor plug or
the KD Valve to put WOT line pressure on the 1-2 governor plug.
2 Allows either the manual valve to put line pressure on the 2-3 governor plug or
the KD Valve to put WOT line pressure on the 2-3 governor plug.
3 Allows either the Reverse circuit or the 3rd gear circuit to pressurize the front
clutch.
4 Allows either the Manual Low circuit from the Manual Valve or the Reverse
from the Manual Valve circuit to pressurize the rear servo.
5 Directs line pressure to the spring end of the 2-3 shift valve in either Manual
Low or Manual 2nd, forcing the downshift to 2nd gear regardless of governor
pressure.
6 Provides a by-pass around the front servo orifice so that the servo can release
quickly.
7 Provides a by-pass around the rear clutch orifice so that the clutch can release
quickly.
8 Directs reverse line pressure through an orifice to the throttle valve eliminating
the extra leakage and insuring that Reverse line pressure pressure will be
sufficient.
9 Provides a by-pass around the rear servo orifice so that the servo can release
quickly.
ECE (10) Allows the lockup clutch to used at WOT in 3rd gear by putting line pressure
from the 3-4 Timing Valve on the interlock area of the 2-3 shift valve, thereby
preventing a 3rd gear Lock-up to 2nd gear kickdown.
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 223
VALVE BODY (Continued)

REGULATOR VALVE
The pressure regulator valve is needed to control
the hydraulic pressure within the system and reduce
the amount of heat produced in the fluid. The pres-
sure regulator valve is located in the valve body near
the manual valve. The pressure regulator valve train
controls the maximum pressure in the lines by
metering the dumping of fluid back into the sump.
Regulated pressure is referred to as ªline pressure.º
The regulator valve (Fig. 251) has a spring on one
end that pushes the valve to the left. This closes a
dump (vent) that is used to lower pressure. The clos-
ing of the dump will cause the oil pressure to
increase. Oil pressure on the opposite end of the
valve pushes the valve to the right, opening the
dump and lowering oil pressure. The result is spring
pressure working against oil pressure to maintain
the oil at specific pressures. With the engine run-
ning, fluid flows from the pump to the pressure reg-
ulator valve, manual valve, and the interconnected
circuits. As fluid is sent through passages to the reg-
ulator valve, the pressure pushes the valve to the
right against the large spring. It is also sent to the
reaction areas on the left side of the throttle pressure
plug and the line pressure plug. With the gear selec-
tor in the PARK position, fluid recirculates through
the regulator and manual valves back to the sump.Meanwhile, the torque converter is filled slowly. In
all other gear positions (Fig. 252), fluid flows
between two right side lands to the switch valve and
torque converter. At low pump speeds, the flow is
controlled by the pressure valve groove to reduce
pressure to the torque converter. After the torque
converter and switch valve fill with fluid, the switch
valve becomes the controlling metering device for
torque converter pressure. The regulator valve then
begins to control the line pressure for the other
transmission circuits. The balance of the fluid pres-
sure pushing the valve to the right and the spring
pressure pushing to the left determines the size of
the metering passage at land #2 (land #1 being at
the far right of the valve in the diagram). As fluid
leaks past the land, it moves into a groove connected
to the filter or sump. As the land meters the fluid to
the sump, it causes the pressure to reduce and the
spring decreases the size of the metering passage.
When the size of the metering passage is reduced,
the pressure rises again and the size of the land is
increased again. Pressure is regulated by this con-
stant balance of hydraulic and spring pressure.
Fig. 251 Regulator Valve in PARK Position
21 - 224 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

The metering at land #2 establishes the line pres-
sure throughout the transmission. It is varied accord-
ing to changes in throttle position and the
transmission's internal condition within a range of
57-94 psi (except in REVERSE) (Fig. 253). The regu-
lated line pressure in REVERSE (Fig. 254) is held at
much higher pressures than in the other gear posi-
tions: 145-280 psi. The higher pressure for
REVERSE is achieved by the manual valve blocking
the supply of line pressure to the reaction area left of
land #4. With this pressure blocked, there is less
area for pressure to act on to balance the force of the
spring on the right. This allows line pressure to push
the valve train to the right, reducing the amount of
fluid returned to the pump's inlet, increasing line
pressure.KICKDOWN VALVE
When the throttle valve is as far over to the left as
it can go, the maximum line pressure possible will
enter the throttle pressure circuit. In this case, throt-
tle pressure will equal line pressure. With the kick-
down valve (Fig. 255) pushed into the bore as far as
it will go, fluid initially flows through the annular
groove of the 2-3 shift valve (which will be in the
direct drive position to the right).
After passing the annular groove, the fluid is
routed to the spring end of the 2-3 shift valve. Fluid
pressure reacting on the area of land #1 overcomes
governor pressure, downshifting the 2-3 shift valve
into the kickdown, or second gear stage of operation.
The valve is held in the kickdown position by throttle
pressure routed from a seated check ball (#2). Again,
if vehicle speed is low enough, throttle pressure will
also push the 1-2 shift valve left to seat its governor
plug, and downshift to drive breakaway.
Fig. 252 Regulator Valve in NEUTRAL Position
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 225
VALVE BODY (Continued)

Fig. 253 Regulator Valve in DRIVE Position
Fig. 254 Regulator Valve in REVERSE Position
21 - 226 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

KICKDOWN LIMIT VALVE
The purpose of the limit valve is to prevent a 3-2
downshift at higher speeds when a part-throttle
downshift is not desirable. At these higher speeds
only a full throttle 3-2 downshift will occur. At low
road speeds (Fig. 256) the limit valve does not come
into play and does not affect the downshifts. As the
vehicle's speed increases (Fig. 257), the governor
pressure also increases. The increased governor pres-
sure acts on the reaction area of the bottom land of
the limit valve overcoming the spring force trying to
push the valve toward the bottom of its bore. This
pushes the valve upward against the spring and bot-
toms the valve against the top of the housing. With
the valve bottomed against the housing, the throttle
pressure supplied to the valve will be closed off by
the bottom land of the limit valve. When the supply
of throttle pressure has been shut off, the 3-2 part
throttle downshift plug becomes inoperative, because
no pressure is acting on its reaction area.
1-2 SHIFT VALVE
The 1-2 shift valve assembly (Fig. 258), or mecha-
nism, consists of: the 1-2 shift valve, governor plug,
and a spring on the end of the valve. After the man-
ual valve has been placed into a forward gear range,
line pressure is directed to the 1-2 shift valve. As the
throttle is depressed, throttle pressure is applied to
the right side of the 1-2 shift valve assembly. With
throttle pressure applied to the right side of the
valve, there is now both spring pressure and throttle
pressure acting on the valve, holding it against the
governor plug. As the vehicle begins to move and
build speed, governor pressure is created and is
applied to the left of the valve at the governor plug.
When governor pressure builds to a point where it
can overcome the combined force of the spring and
throttle pressure on the other side of the valve, the
valve will begin to move over to the right. As the
valve moves to the right, the middle land of the valve
will close off the circuit supplying the throttle pres-
sure to the right side of the valve. When the throttle
Fig. 255 Kickdown Valve-Wide Open Throttle
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 227
VALVE BODY (Continued)