2001 DODGE RAM lock

OPERATION
The converter impeller (Fig. 240) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft (Fig. 241).
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-clockwise direction. When this happens the overrun-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.4:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
TORQUE CONVERTER CLUTCH (TCC)
The torque converter clutch is hydraulically
applied and is released when fluid is vented from the
hydraulic circuit by the torque converter control
(TCC) solenoid on the valve body. The torque con-
verter clutch is controlled by the Powertrain Control
Module (PCM). The torque converter clutch engages
in fourth gear, and in third gear under various con-
ditions, such as when the O/D switch is OFF, when
the vehicle is cruising on a level surface after the
vehicle has warmed up. The torque converter clutch
will disengage momentarily when an increase in
engine load is sensed by the PCM, such as when the
Fig. 240 Torque Converter Fluid Operation
1 - APPLY PRESSURE 3 - RELEASE PRESSURE
2 - THE PISTON MOVES SLIGHTLY FORWARD 4 - THE PISTON MOVES SLIGHTLY REARWARD
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TORQUE CONVERTER (Continued)

vehicle begins to go uphill or the throttle pressure is
increased.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.
(1) Lubricate oil pump seal lip with transmission
fluid.
(2) Place torque converter in position on transmis-
sion.CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.
(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 242). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle.
(9) Fill the transmission with the recommended
fluid.
Fig. 241 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
Fig. 242 Checking Torque Converter Seating -
Typical
1 - SCALE
2 - STRAIGHTEDGE
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TORQUE CONVERTER (Continued)

TORQUE CONVERTER
DRAINBACK VALVE
DESCRIPTION
The drainback valve is located in the transmission
cooler outlet (pressure) line.
OPERATION
The valve prevents fluid from draining from the
converter into the cooler and lines when the vehicle
is shut down for lengthy periods. Production valves
have a hose nipple at one end, while the opposite end
is threaded for a flare fitting. All valves have an
arrow (or similar mark) to indicate direction of flow
through the valve.
STANDARD PROCEDURE - TORQUE
CONVERTER DRAINBACK VALVE
The converter drainback check valve is located in
the cooler outlet (pressure) line near the radiator
tank. The valve prevents fluid drainback when the
vehicle is parked for lengthy periods. The valve check
ball is spring loaded and has an opening pressure of
approximately 2 psi.
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. 243). 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 1000 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).
Fig. 243 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
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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. 244), (Fig. 245), (Fig.
246), and (Fig. 247):
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 valve²2-3 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. 244 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
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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.
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VALVE BODY (Continued)

57-94 psi (except in REVERSE) (Fig. 250). The regu-
lated line pressure in REVERSE (Fig. 251) 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 ofland #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.
Fig. 249 Regulator Valve in NEUTRAL Position
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VALVE BODY (Continued)

1-2 SHIFT VALVE
The 1-2 shift valve assembly (Fig. 255), 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. 256).
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. 255 1-2 Shift Valve-Before Shift
Fig. 256 1-2 Shift Valve-After Shift
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VALVE BODY (Continued)

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. 257):
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. 258) 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 overcome the combined throttle and spring pressure
on the right side of the valve. Since the throttle pres-
sure 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 mov-
ing it to the right. The shift valve causes land #4 to
close the passage supplying throttle pressure to the 2-3
shift valve. Without throttle pressure present in the cir-
cuit 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 pressure to the front clutch.
After the shift (Fig. 259), 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. 257 1-2 Shift Control Valve
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VALVE BODY (Continued)