sensor DODGE RAM 2001 Service Repair Manual

where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
across the solenoid to allow either full flow or no flow
through the solenoid's valve.
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path for
the magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
SPEED SENSOR
DESCRIPTION
The speed sensor (Fig. 231) is located in the over-
drive gear case. The sensor is positioned over the
park gear and monitors transmission output shaft
rotating speed.
OPERATION
Speed sensor signals are triggered by the park
gear lugs as they rotate past the sensor pickup face.
Input signals from the sensor are sent to the trans-
mission control module for processing. Signals from
this sensor are shared with the powertrain control
module.
THROTTLE VALVE CABLE
DESCRIPTION
Transmission throttle valve cable (Fig. 232) adjust-
ment is extremely important to proper operation.
This adjustment positions the throttle valve, which
controls shift speed, quality, and part-throttle down-
shift sensitivity.
If cable setting is too loose, early shifts and slip-
page between shifts may occur. If the setting is too
tight, shifts may be delayed and part throttle down-
shifts may be very sensitive.
Fig. 231 Transmission Output Speed Sensor
1 - TRANSMISSION OUTPUT SHAFT SPEED SENSOR
2 - SEAL
Fig. 232 Throttle Valve Cable Attachment - At
Engine
1 - THROTTLE VALVE CABLE
2 - CABLE BRACKET
3 - THROTTLE BODY LEVER
4 - ACCELERATOR CABLE
5 - SPEED CONTROL CABLE
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 597
SOLENOID (Continued)

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. 246). The temperature readings are used
to control engagement of the fourth gear overdriveclutch, 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. 246 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
21 - 606 AUTOMATIC TRANSMISSION - 46REBR/BE
TORQUE CONVERTER DRAINBACK VALVE (Continued)

BOOST VALVE
The boost valve (Fig. 269) provides increased fluid
apply pressure to the overdrive clutch during 3-4
upshifts (Fig. 270), 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.
²Manual 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. 271).
(5) Position drain pan under transmission oil pan.
(6) Remove transmission oil pan and gasket.
(7) Remove fluid filter from valve body.
(8) Remove bolts attaching valve body to transmis-
sion case.
(9) Lower valve body enough to remove accumula-
tor piston and springs.
(10) Work manual lever shaft and electrical con-
nector out of transmission case.
(11) Lower valve body, rotate valve body away
from case, pull park rod out of sprag, and remove
valve body (Fig. 272).
Fig. 269 Boost Valve Before Lock-up
Fig. 270 Boost Valve After Lock-up
Fig. 271 Transmission Case Connector
1 - SOLENOID CASE CONNECTOR
2 - PARK/NEUTRAL POSITION SWITCH
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 625
VALVE BODY (Continued)

DISASSEMBLY
CAUTION: Do not clamp any valve body component
in a vise. This practice can damage the component
resulting in unsatisfactory operation after assembly
and installation. Do not use pliers to remove any of
the valves, plugs or springs and do not force any of
the components out or into place. The valves and
valve body housings will be damaged if force is
used. Tag or mark the valve body springs for refer-
ence as they are removed. Do not allow them to
become intermixed.
(1) Disconnect wires from governor pressure sen-
sor and solenoid.
(2) Remove screws attaching governor body and
retainer plate to transfer plate.
(3) Remove retainer plate, governor body and gas-
ket from transfer plate.(4) Remove governor pressure sensor from gover-
nor body.
(5) Remove governor pressure solenoid by pulling
it straight out of bore in governor body. Remove and
discard solenoid O-rings if worn, cut, or torn.
(6) Remove small shoulder bolt that secures sole-
noid harness case connector to 3-4 accumulator hous-
ing (Fig. 273). Retain shoulder bolt. Either tape it to
harness or thread it back into accumulator housing
after connector removal.
(7) Unhook overdrive/converter solenoid harness
from 3-4 accumulator cover plate (Fig. 274).Fig. 273 Solenoid Harness Case Connector
Shoulder Bolt
1 - SOLENOID HARNESS CASE CONNECTOR
2 - 3-4 ACCUMULATOR HOUSING
Fig. 274 Solenoid Harness Routing
1 - OVERDRIVE/CONVERTER SOLENOID WIRE HARNESS
2 - 3-4 ACCUMULATOR COVER PLATE
Fig. 272 Valve Body
1 - VALVE BODY
2 - WIRE HARNESS
3 - PARK ROD
4 - GOVERNOR PRESSURE SOLENOID
5 - GOVERNOR PRESSURE SENSOR
21 - 626 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

(8) Turn valve body over and remove screws that
attach overdrive/converter solenoid assembly to valve
body (Fig. 275).
(9) Remove solenoid and harness assembly from
valve body (Fig. 276).(10) Remove boost valve cover (Fig. 277).
(11) Remove boost valve retainer, valve spring and
boost valve (Fig. 278).
Fig. 275 Solenoid Assembly Screws
1 - OVERDRIVE/CONVERTER CLUTCH SOLENOID ASSEMBLY
2 - HARNESS
Fig. 276 Solenoid Assembly
1 - GOVERNOR SOLENOID WIRES
2 - CONVERTER CLUTCH SOLENOID
3 - SOLENOID SCREWS
4 - GOVERNOR SENSOR WIRES
5 - OVERDRIVE SOLENOID
6 - HARNESS
7 - CASE CONNECTOR
Fig. 277 Boost Valve Cover Location
1 - BOOST VALVE HOUSING AND COVER
2 - BOOST VALVE TUBE
Fig. 278 Boost Valve Components
1 - SPRING AND VALVE RETAINER
2 - COVER SCREWS
3 - BOOST VALVE COVER
4 - BOOST VALVE PLUG
5 - BOOST VALVE
6 - BOOST VALVE SPRING
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 627
VALVE BODY (Continued)

3-4 ACCUMULATOR HOUSING
(1) Remove end plate from housing.
(2) Remove piston spring.
(3) Remove piston. Remove and discard piston
seals (Fig. 302).
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 eitherpart 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, the
filter 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
Fig. 302 3-4 Accumulator and Housing
1 - ACCUMULATOR PISTON
2 - 3-4 ACCUMULATOR HOUSING
3 - TEFLON SEALS
4 - PISTON SPRING
5 - COVER PLATE AND SCREWS
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 637
VALVE BODY (Continued)

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.
Valve body bores do not change dimensionally with
use. If the valve body functioned correctly when new,
it will continue to operate properly after cleaning and
inspection. It should not be necessary to replace a
valve body assembly unless it is damaged in han-
dling.
The only serviceable valve body components are
listed below. The remaining valve body components
are serviced only as part of a complete valve body
assembly. Serviceable parts are:
²dual solenoid and harness assembly
²solenoid gasket
²
solenoid case connector O-rings and shoulder bolt
²switch valve and spring
²pressure adjusting screw and bracket assembly
²throttle lever
²manual lever and shaft seal
²throttle lever shaft seal, washer, and E-clip
²fluid filter and screws
²detent ball and spring
²valve body screws
²governor pressure solenoid
²governor pressure sensor and retaining clip
²park lock rod and E-clip
ASSEMBLY
CAUTION: Do not force valves or plugs into place
during reassembly. If the valve body bores, valves
and plugs are free of distortion or burrs, the valve
body components should all slide into place easily.
In addition, do not overtighten the transfer plate
and valve body screws during reassembly. Over-
tightening can distort the housings resulting in
valve sticking, cross leakage and unsatisfactory
operation. Tighten valve body screws to recom-
mended torque only.
LOWER HOUSING
(1) Lubricate valves, springs, and the housing
valve and plug bores with clean transmission fluid
(Fig. 298).
(2) Install 3-4 timing valve spring and valve in
lower housing.
(3) Install 3-4 quick fill valve in lower housing.
(4)
Install 3-4 quick fill valve spring and plug in
housing.
(5) Install timing valve end plate. Tighten end
plate screws to 4 N´m (35 in. lbs.) torque.
3-4 ACCUMULATOR
(1)Lubricate accumulator piston, seals and housing
piston bore with clean transmission fluid (Fig. 299).
(2) Install new seal rings on accumulator piston.
(3) Install piston and spring in housing.
(4) Install end plate on housing.
TRANSFER PLATE
(1) Install rear clutch and rear servo check balls in
transfer plate (Fig. 303).
(2) Install filter screen in upper housing separator
plate (Fig. 304).
(3) Align and position upper housing separator
plate on transfer plate (Fig. 305).
(4) Install brace plate (Fig. 305). Tighten brace
attaching screws to 4 N´m (35 in. lbs.) torque.
(5) Install remaining separator plate attaching
screws. Tighten screws to 4 N´m (35 in. lbs.) torque.
Fig. 303 Rear Clutch And Rear Servo Check Ball
Locations
1 - REAR CLUTCH CHECK BALL
2 - REAR SERVO CHECK BALL
3 - TRANSFER PLATE
Fig. 304 Separator Plate Filter Screen Installation
1 - UPPER HOUSING SEPARATOR PLATE
2 - FILTER SCREEN
21 - 638 AUTOMATIC TRANSMISSION - 46REBR/BE
VALVE BODY (Continued)

(17) Perform Line Pressure and Throttle Pressure
adjustments. (Refer to 21 - TRANSMISSION/TRAN-
SAXLE/AUTOMATIC/VALVE BODY - ADJUST-
MENTS)
(18) Lubricate solenoid case connector O-rings and
shaft of manual lever with light coat of petroleum
jelly.
(19) Attach solenoid case connector to 3-4 accumu-
lator with shoulder-type screw. Connector has small
locating tang that fits in dimple at top of accumula-
tor housing (Fig. 320). Seat tang in dimple before
tightening connector screw.
(20) Install solenoid assembly and gasket. Tighten
solenoid attaching screws to 8 N´m (72 in. lbs.)
torque.
(21) Verify that solenoid wire harness is properly
routed (Fig. 321). Solenoid harness must be clear of
manual lever and park rod and not be pinched
between accumulator housing and cover.
GOVERNOR BODY, SENSOR AND SOLENOID
(1) Turn valve body assembly over so accumulator
side of transfer plate is facing down.
(2) Install new O-rings on governor pressure sole-
noid and sensor.
(3) Lubricate solenoid and sensor O-rings with
clean transmission fluid.
(4) Install governor pressure sensor in governor
body.
(5) Install governor pressure solenoid in governor
body. Push solenoid in until it snaps into place in
body.
(6) Position governor body gasket on transfer
plate.(7) Install retainer plate on governor body and
around solenoid. Be sure solenoid connector is posi-
tioned in retainer cutout.
(8) Align screw holes in governor body and trans-
fer plate. Then install and tighten governor body
screws to 4 N´m (35 in. lbs.) torque.
(9) Connect harness wires to governor pressure
solenoid and governor pressure sensor.
(10) Install fluid filter and pan.
(11) Lower vehicle.
(12) Fill transmission with recommended fluid and
road test vehicle to verify repair.
INSTALLATION
(1) Check condition of O-ring seals on valve body
harness connector (Fig. 322). Replace seals on con-
nector body if cut or worn.
(2) Check condition of manual lever shaft seal in
transmission case. Replace seal if lip is cut or worn.
Install new seal with 15/16 deep well socket (Fig.
323).
(3) Check condition of seals on accumulator piston
(Fig. 324). Install new piston seals, if necessary.
(4) Place valve body manual lever in low (1 posi-
tion) so ball on park lock rod will be easier to install
in sprag.
(5) Lubricate shaft of manual lever with petroleum
jelly. This will ease inserting shaft through seal in
case.
(6) Lubricate seal rings on valve body harness con-
nector with petroleum jelly.
(7) Position valve body in case and work end of
park lock rod into and through pawl sprag. Turn pro-
peller shaft to align sprag and park lock teeth if nec-
essary. The rod will click as it enters pawl. Move rod
to check engagement.Fig. 320 Solenoid Harness Case Connector
Shoulder Bolt
1 - SOLENOID HARNESS CASE CONNECTOR
2 - 3-4 ACCUMULATOR HOUSING
Fig. 321 Solenoid Harness Routing
1 - OVERDRIVE/CONVERTER SOLENOID WIRE HARNESS
2 - 3-4 ACCUMULATOR COVER PLATE
BR/BEAUTOMATIC TRANSMISSION - 46RE 21 - 645
VALVE BODY (Continued)

OVERRUNNING CLUTCH CAM/OVERDRIVE
PISTON RETAINER
DESCRIPTION..........................751
OPERATION............................751
DISASSEMBLY..........................751
CLEANING.............................752
INSPECTION...........................752
ASSEMBLY............................752
PARK/NEUTRAL POSITION SWITCH
DIAGNOSIS AND TESTING................755
PARK/NEUTRAL POSITION SWITCH.......755
REMOVAL.............................755
INSTALLATION..........................755
PISTONS
DESCRIPTION..........................755
OPERATION............................755
PLANETARY GEARTRAIN/OUTPUT SHAFT
DESCRIPTION..........................757
OPERATION............................757
DISASSEMBLY..........................757
INSPECTION...........................760
ASSEMBLY............................760
REAR CLUTCH
DESCRIPTION..........................764
OPERATION............................764
DISASSEMBLY..........................765
CLEANING.............................765
INSPECTION...........................765
ASSEMBLY............................766
REAR SERVO
DESCRIPTION..........................767
OPERATION............................767
DISASSEMBLY..........................768
CLEANING.............................768
ASSEMBLY............................768
SHIFT MECHANISM
DESCRIPTION..........................768OPERATION............................768
ADJUSTMENTS.........................769
SOLENOID
DESCRIPTION..........................769
OPERATION............................770
SPEED SENSOR
DESCRIPTION..........................770
OPERATION............................770
THROTTLE VALVE CABLE
DESCRIPTION..........................770
ADJUSTMENTS.........................771
TORQUE CONVERTER
DESCRIPTION..........................773
OPERATION............................777
REMOVAL.............................778
INSTALLATION..........................778
TORQUE CONVERTER DRAINBACK VALVE
DESCRIPTION..........................778
OPERATION............................778
STANDARD PROCEDURE.................778
TORQUE CONVERTER DRAINBACK VALVE . 778
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION..........................779
OPERATION............................779
VALVE BODY
DESCRIPTION..........................780
OPERATION............................783
REMOVAL.............................798
DISASSEMBLY..........................799
CLEANING.............................808
INSPECTION...........................809
ASSEMBLY............................810
INSTALLATION..........................818
ADJUSTMENTS.........................818
AUTOMATIC TRANSMISSION -
47RE
DESCRIPTION
The 47RE (Fig. 1) is a four speed fully automatic
transmissions with an electronic governor. The 47RE
is equipped with a lock-up clutch in the torque con-
verter. First through third gear ranges are provided
by the clutches, bands, overrunning clutch, and plan-
etary gear sets in the transmission. Fourth gear
range is provided by the overdrive unit that contains
an overdrive clutch, direct clutch, planetary gear set,
and overrunning clutch.
The transmission contains a front, rear, and direct
clutch which function as the input driving compo-
nents. It also contains the kickdown (front) and thelow/reverse (rear) bands which, along with the over-
running clutch and overdrive clutch, serve as the
holding components. The driving and holding compo-
nents combine to select the necessary planetary gear
components, in the front, rear, or overdrive planetary
gear set, transfer the engine power from the input
shaft through to the output shaft.
The valve body is mounted to the lower side of the
transmission and contains the valves to control pres-
sure regulation, fluid flow control, and clutch/band
application. The oil pump is mounted at the front of
the transmission and is driven by the torque con-
verter hub. The pump supplies the oil pressure nec-
essary for clutch/band actuation and transmission
lubrication.
BR/BEAUTOMATIC TRANSMISSION - 47RE 21 - 649

FOURTH GEAR POWERFLOW
Fourth gear overdrive range is electronically con-
trolled and hydraulically activated. Various sensor
inputs are supplied to the powertrain control module
to operate the overdrive solenoid on the valve body.
The solenoid contains a check ball that opens and
closes a vent port in the 3-4 shift valve feed passage.
The overdrive solenoid (and check ball) are not ener-
gized in first, second, third, or reverse gear. The vent
port remains open, diverting line pressure from the
2-3 shift valve away from the 3-4 shift valve. The
overdrive control switch must be in the ON position
to transmit overdrive status to the PCM. A 3-4
upshift occurs only when the overdrive solenoid is
energized by the PCM. The PCM energizes the over-
drive solenoid during the 3-4 upshift. This causes the
solenoid check ball to close the vent port allowing
line pressure 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. 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. Line pressure through the timing
valve moves the overdrive piston into contact with
the overdrive clutch. The direct clutch is disengaged
before the overdrive clutch is engaged. The boost
valve provides increased fluid apply pressure to the
overdrive clutch during 3-4 upshifts, and when accel-
erating in fourth gear. The 3-4 accumulator cushions
overdrive clutch engagement to smooth 3-4 upshifts.
The accumulator is charged at the same time as
apply pressure acts against the overdrive piston.
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION
Automatic transmission problems can be a result of
poor engine performance, incorrect fluid level, incor-
rect linkage or cable adjustment, band or hydraulic
control pressure adjustments, hydraulic system mal-
functions or electrical/mechanical component mal-
functions. Begin diagnosis by checking the easily
accessible items such as: fluid level and condition,
linkage adjustments and electrical connections. A
road test will determine if further diagnosis is neces-
sary.
DIAGNOSIS AND TESTING - PRELIMINARY
Two basic procedures are required. One procedure
for vehicles that are drivable and an alternate proce-
dure for disabled vehicles (will not back up or move
forward).
VEHICLE IS DRIVEABLE
(1) Check for transmission fault codes using DRBt
scan tool.
(2) Check fluid level and condition.
(3) Adjust throttle and gearshift linkage if com-
plaint was based on delayed, erratic, or harsh shifts.
(4) Road test and note how transmission upshifts,
downshifts, and engages.
(5) Perform hydraulic pressure test if shift prob-
lems were noted during road test.
(6) Perform air-pressure test to check clutch-band
operation.
VEHICLE IS DISABLED
(1) Check fluid level and condition.
(2) Check for broken or disconnected gearshift or
throttle linkage.
(3) Check for cracked, leaking cooler lines, or loose
or missing pressure-port plugs.
(4) Raise and support vehicle on safety stands,
start engine, shift transmission into gear, and note
following:
(a) If propeller shaft turns but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shaft does not turn and transmis-
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis-
sion and check for damaged drive plate, converter,
oil pump, or input shaft.
(c) If propeller shaft does not turn and transmis-
sion is not noisy, perform hydraulic-pressure test to
determine if problem is hydraulic or mechanical.
DIAGNOSIS AND TESTING - ROAD TESTING
Before road testing, be sure the fluid level and con-
trol cable adjustments have been checked and
adjusted if necessary. Verify that diagnostic trouble
codes have been resolved.
Observe engine performance during the road test.
A poorly tuned engine will not allow accurate analy-
sis of transmission operation.
Operate the transmission in all gear ranges. Check
for shift variations and engine flare which indicates
slippage. Note if shifts are harsh, spongy, delayed,
early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means
clutch, band or overrunning clutch problems. If the
condition is advanced, an overhaul will be necessary
to restore normal operation.
A slipping clutch or band can often be determined
by comparing which internal units are applied in the
various gear ranges. The Clutch and Band Applica-
tion chart provides a basis for analyzing road test
results.
BR/BEAUTOMATIC TRANSMISSION - 47RE 21 - 657
AUTOMATIC TRANSMISSION - 47RE (Continued)