app DODGE RAM 2003 Service Repair Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 2003, Model line: RAM, Model: DODGE RAM 2003Pages: 2895, PDF Size: 83.15 MB
Page 2117 of 2895

1-2 SHIFT VALVE
The 1-2 shift valve assembly (Fig. 278), 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 throttlepressure is closed off, the valve will move even far-
ther to the right, allowing line pressure to enter
another circuit and energize the front servo, applying
the front band (Fig. 279).
The governor plug serves a dual purpose:
²It allows the shift valves to move either left or
right, allowing both upshifts and downshifts.
²When in a manual selection position, it will be
hydraulically ªblockedº into position so no upshift can
occur.
The physical blocking of the upshift while in the
manual ª1º position is accomplished by the directing
of line pressure between both lands of the governor
plug. The line pressure reacts against the larger land
of the plug, pushing the plug back against the end
plate overcoming governor pressure. With the combi-
nation of the line pressure and spring pressure, the
valve cannot move, preventing any upshift.
Fig. 278 1-2 Shift Valve-Before Shift
Fig. 279 1-2 Shift Valve-After Shift
21 - 278 AUTOMATIC TRANSMISSION - 46REDR
VALVE BODY (Continued)
Page 2118 of 2895

1-2 SHIFT CONTROL VALVE
It contains a valve with four lands and a spring. It
is used as both a ªrelayº and ªbalancedº valve.
The valve has two specific operations (Fig. 280):
²Aid in quality of the 1-2 upshift.
²Aid in the quality and timing of the 3-2 kick-
down ranges.
When the manual valve is set to the DRIVE position
and the transmission is in the first or second gear range,
1-2 shift control or ªmodulated throttle pressureº is sup-
plied to the middle of the accumulator piston by the 1-2
shift control valve. During the 1-2 upshift, this pressure
is used to control the kickdown servo apply pressure that
is needed to apply the kickdown and accumulator pis-
tons. Thus, the 1-2 shift point is ªcushionedº and the
quality is improved. During a WOT kickdown, kickdown
pressure is applied between the kickdown valve and the
1-2 shift control valve. This additional pressure is
directed to the 1-2 shift control's spring cavity, adding to
the spring load on the valve. The result of this increased
ªmodulatedº throttle pressure is a firmer WOT upshift.
2-3 SHIFT VALVE
The 2-3 shift valve mechanism (Fig. 281) consists of
the 2-3 shift valve, governor plug and spring, and a
throttle plug. After the 1-2 shift valve has completed its
operation and applied the front band, line pressure is
directed to the 2-3 shift valve through the connecting
passages from the 1-2 shift valve. The line pressure will
then dead±end at land #2 until the 2-3 valve is ready to
make its shift. Now that the vehicle is in motion andunder acceleration, there is throttle pressure being
applied to the spring side of the valve and between
lands #3 and #4.
As vehicle speed increases, governor pressure increases
proportionately, until it becomes great enough to over-
come the combined throttle and spring pressure on the
right side of the valve. Since the throttle pressure end of
the 2-3 shift valve is larger in diameter than the 1-2 shift
valve, the 2-3 shift will always happen at a greater speed
than the 1-2 shift. When this happens, the governor plug
is forced against the shift valve moving it to the right.
The shift valve causes land #4 to close the passage sup-
plying throttle pressure to the 2-3 shift valve. Without
throttle pressure present in the circuit now, the governor
plug will push the valve over far enough to bottom the
valve in its bore. This allows land #2 to direct line pres-
sure to the front clutch.
After the shift (Fig. 282), line pressure is directed
to the land between the shift valve and the governor
plug, and to the release side of the kickdown servo.
This releases the front band and applies the front
clutch, shifting into third gear or direct drive. The
rear clutch remains applied, as it has been in the
other gears. During a manual ª1º or manual ª2º gear
selection, line pressure is sent between the two lands
of the 2-3 governor plug. This line pressure at the
governor plug locks the shift valve into the second
gear position, preventing an upshift into direct drive.
The theory for the blocking of the valve is the same
as that of the 1-2 shift valve.
Fig. 280 1-2 Shift Control Valve
DRAUTOMATIC TRANSMISSION - 46RE 21 - 279
VALVE BODY (Continued)
Page 2120 of 2895

3-4 SHIFT VALVE
The PCM energizes the overdrive solenoid during
the 3-4 upshift (Fig. 283). This causes the solenoid
check ball to close the vent port allowing line pres-
sure from the 2-3 shift valve to act directly on the 3-4
upshift valve. Line pressure on the 3-4 shift valve
overcomes valve spring pressure moving the valve to
the upshift position (Fig. 284). This action exposes
the feed passages to the 3-4 timing valve, 3-4 quick
fill valve, 3-4 accumulator, and ultimately to the
overdrive piston.
3-4 TIMING VALVE
The 3-4 timing valve is moved by line pressure
coming through the 3-4 shift valve (Fig. 284). After
the shift, the timing valve holds the 2-3 shift valve in
an upshift position. The purpose is to prevent the 2-3
valve from downshifting before the 3-4 valve (Fig.
283).
3-4 QUICK FILL VALVE
The 3-4 quick fill valve provides faster engagement
of the overdrive clutch during 3-4 upshifts. The valve
temporarily bypasses the clutch piston feed orifice at
the start of a 3-4 upshift (Fig. 283). 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 ori-
fice throughout the 3-4 upshift. Instead, once a pre-
determined pressure develops within the clutch, the
valve closes the bypass (Fig. 284). Clutch fill is then
completed through the regular feed orifice.
Fig. 283 3-4 Shift Valve Before Shift
Fig. 284 3-4 Shift Valve After Shift
DRAUTOMATIC TRANSMISSION - 46RE 21 - 281
VALVE BODY (Continued)
Page 2121 of 2895

THROTTLE VALVE
In all gear positions the throttle valve (Fig. 285) 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, 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 regu-
lated to maintain the balance within the transmis-
sion. To do this, throttle pressure is routed to the
reaction area on the right side of the throttle pres-
sure 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 move-
ment of the pressure valve to help control the meter-
ing 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 regulator 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 regu-
lator valve train to the right and controls the meter-
ing 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 kick-
down valve is actuated by a cam connected to the
throttle. This is accomplished through either a link-
age 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 ªmeteredº 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.
Fig. 285 Throttle Valve
21 - 282 AUTOMATIC TRANSMISSION - 46REDR
VALVE BODY (Continued)
Page 2122 of 2895

SWITCH VALVE
When the transmission is in Drive Second before the
TCC application occurs (Fig. 286), 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. 286 Switch Valve-Torque Converter Unlocked
DRAUTOMATIC TRANSMISSION - 46RE 21 - 283
VALVE BODY (Continued)
Page 2123 of 2895

Once the TCC control valve has moved to the right
(Fig. 287), 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.
Fig. 287 Switch Valve-Torque Converter Locked
21 - 284 AUTOMATIC TRANSMISSION - 46REDR
VALVE BODY (Continued)
Page 2124 of 2895

MANUAL VALVE
The manual valve (Fig. 288) 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 gear-
shift mechanism. The valve is held in each of its
positions by a spring-loaded roller or ball that
engages the ªroostercombº of the manual valve lever.
CONVERTER CLUTCH LOCK-UP VALVE
The torque converter clutch (TCC) lock-up valve
controls the back (ON) side of the torque converter
clutch. When the PCM energizes the TCC solenoid to
engage the converter clutch piston, pressure is
applied to the TCC lock-up valve which moves to the
right and applies pressure to the torque converter
clutch.
CONVERTER CLUTCH LOCK-UP TIMING VALVE
The torque converter clutch (TCC) lock-up timing
valve is there to block any 4-3 downshift until the
TCC is completely unlocked and the clutch is disen-
gaged.
SHUTTLE VALVE
The assembly is contained in a bore in the valve
body above the shift valves. When the manual valve
is positioned in the Drive range, throttle pressure
acts on the throttle plug of the shuttle valve (Fig.
280) to move it against a spring, increasing the
spring force on the shuttle valve. During a part or
full throttle 1-2 upshift, the throttle plug is bottomed
by throttle pressure, holding the shuttle valve to the
right against governor pressure, and opening a
by±pass circuit. The shuttle valve controls the qual-
ity of the kickdown shift by restricting the rate of
fluid discharge from the front clutch and servo
release circuits. During a 3-2 kickdown, fluid dis-
charges through the shuttle by-pass circuit. When
the shuttle valve closes the by-pass circuit, fluid dis-
charge is restricted and controlled for the application
of the front band. During a 2-3 ªlift footº upshift, the
shuttle valve by-passes the restriction to allow full
fluid flow through the by-pass groove for a faster
release of the band.
Fig. 288 Manual Valve
DRAUTOMATIC TRANSMISSION - 46RE 21 - 285
VALVE BODY (Continued)
Page 2125 of 2895

BOOST VALVE
The boost valve (Fig. 289) provides increased fluid
apply pressure to the overdrive clutch during 3-4
upshifts (Fig. 290), and when accelerating in fourth
gear. The boost valve also serves to increase line
pressure during torque converter lock-up.
REMOVAL
The valve body can be removed for service without
having to remove the transmission assembly.
The valve body can be disassembled for cleaning
and inspection of the individual components.
The only replaceable valve body components are:
²Manual lever.
²
Manual lever washer, seal, E-clip, and shaft seal.
²Manual lever detent ball.
²Throttle lever.
²Fluid filter.
²Pressure adjusting screw bracket.
²Governor pressure solenoid.
²Governor pressure sensor (includes transmission
temperature thermistor).
²Converter clutch/overdrive solenoid assembly
and harness.
²Governor housing gasket.
²Solenoid case connector O-rings.
(1) Shift transmission into NEUTRAL.
(2) Raise vehicle.
(3) Remove gearshift and throttle levers from shaft
of valve body manual lever.
(4) Disconnect wires at solenoid case connector
(Fig. 291).
(5) Remove the transmission range sensor.
(6) Position drain pan under transmission oil pan.
(7) Remove transmission oil pan and gasket.
(8) Remove fluid filter from valve body.
(9) Remove bolts attaching valve body to transmis-
sion case.
(10) Lower valve body enough to remove accumu-
lator piston and springs.
(11) Work manual lever shaft and electrical con-
nector out of transmission case.
Fig. 291 Transmission Case Connector
1 - SOLENOID CASE CONNECTOR
2 - TRANSMISSION RANGE SENSOR
Fig. 289 Boost Valve Before Lock-up
Fig. 290 Boost Valve After Lock-up
21 - 286 AUTOMATIC TRANSMISSION - 46REDR
VALVE BODY (Continued)
Page 2132 of 2895

(29) Remove the Number 10 check ball from the
transfer plate (Fig. 313). The check ball is approxi-
mately 4.8 mm (3/16 in.) in diameter.
(30) Remove transfer plate from upper housing
(Fig. 314).
(31) Turn transfer plate over so upper housing sep-
arator plate is facing upward.(32) Remove upper housing separator plate from
transfer plate (Fig. 315). Note position of filter in
separator plate for assembly reference.
(33) Remove rear clutch and rear servo check balls
from transfer plate. Note check ball location for
assembly reference (Fig. 316).
Fig. 313 Number 10 Check Ball
1 - NUMBER 10 CHECK BALL (3/169)
Fig. 314 Transfer Plate
1 - UPPER HOUSING
2 - TRANSFER PLATE
Fig. 315 Upper Housing Separator Plate
1 - TRANSFER PLATE
2 - UPPER HOUSING SEPARATOR PLATE
3 - FILTER SCREEN
4 - BRACE
Fig. 316 Rear Clutch and Rear Servo Check Ball
Locations
1 - REAR CLUTCH CHECK BALL
2 - REAR SERVO CHECK BALL
3 - TRANSFER PLATE
DRAUTOMATIC TRANSMISSION - 46RE 21 - 293
VALVE BODY (Continued)
Page 2137 of 2895

CLEANING
Clean the valve housings, valves, plugs, springs,
and separator plates with a standard parts cleaning
solution only. Do not use gasoline, kerosene, or any
type of caustic solution.
Do not immerse any of the electrical components in
cleaning solution. Clean the governor solenoid and
sensor and the dual solenoid and harness assembly
by wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed
air. Make sure all passages are clean and free from
obstructions.Do not use rags or shop towels to
dry or wipe off valve body components. Lint
from these materials can stick to valve body
parts, interfere with valve operation, and clog
filters and fluid passages.
Wipe the governor pressure sensor and solenoid
valve with dry, lint free shop towels only. The O-rings
on the sensor and solenoid valve are the only service-
able components. Be sure the vent ports in the sole-
noid valve are open and not blocked by dirt or debris.
Replace the valve and/or sensor only when DRB scan
tool diagnosis indicates this is necessary. Or, if either
part has sustained physical damage (dented,
deformed, broken, etc.).
CAUTION: Do not turn the small screw at the end of
the solenoid valve for any reason. Turning the
screw in either direction will ruin solenoid calibra-
tion and result in solenoid failure. In addition, thefilter on the solenoid valve is NOT serviceable. Do
not try to remove the filter as this will damage the
valve housing.
INSPECTION
Inspect the throttle and manual valve levers and
shafts. Do not attempt to straighten a bent shaft or
correct a loose lever. Replace these components if
worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for
scratches, nicks, burrs, or distortion. Use a straight-
edge to check surface flatness. Minor scratches may
be removed with crocus cloth using only very light
pressure.
Minor distortion of a valve body mating surface
may be corrected by smoothing the surface with a
sheet of crocus cloth. Position the crocus cloth on a
surface plate, sheet of plate glass or equally flat sur-
face. If distortion is severe or any surfaces are
heavily scored, the valve body will have to be
replaced.
CAUTION: Many of the valves and plugs, such as
the throttle valve, shuttle valve plug, 1-2 shift valve
and 1-2 governor plug, are made of coated alumi-
num. Aluminum components are identified by the
dark color of the special coating applied to the sur-
face (or by testing with a magnet). Do not sand alu-
minum valves or plugs under any circumstances.
This practice could damage the special coating
causing the valves/plugs to stick and bind.
Inspect the valves and plugs for scratches, burrs,
nicks, or scores. Minor surface scratches on steel
valves and plugs can be removed with crocus cloth
butdo not round off the edges of the valve or
plug lands.Maintaining sharpness of these edges is
vitally important. The edges prevent foreign matter
from lodging between the valves and plugs and the
bore.
Inspect all the valve and plug bores in the valve
body. Use a penlight to view the bore interiors.
Replace the valve body if any bores are distorted or
scored. Inspect all of the valve body springs. The
springs must be free of distortion, warpage or broken
coils.
Check the two separator plates for distortion or
damage of any kind. Inspect the upper housing,
lower housing, 3-4 accumulator housing, and transfer
plate carefully. Be sure all fluid passages are clean
and clear. Check condition of the upper housing and
transfer plate check balls as well. The check balls
and ball seats must not be worn or damaged.
Trial fit each valve and plug in its bore to check
freedom of operation. When clean and dry, the valves
and plugs should drop freely into the bores.
Fig. 322 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
21 - 298 AUTOMATIC TRANSMISSION - 46REDR
VALVE BODY (Continued)