1993 DODGE TRUCK check transmission fluid

•

NV4500 MANUAL
TRANSMISSION
21 - 3

PTO

COVER

J9221-14

Fig. 2 NV4500 identification Tag Location
DRAIN

PLUG
J9221-80

Fig. 3 NV4500 Drain And Fill Plug Locations

o
0 ©
0 0©
J9221-13

Fig. 4 NV4500 Shitt Pattern
NOISY OPERATION Transmission noise is most often a result of worn
or damaged components. Chipped, broken gear or
synchronizer teeth and brinnelled, spalled bearings
all cause noise.
Abnormal wear and damage to internal compo­
nents is frequently the end result of insufficient lu­
bricant, non-recommended lubricants, or improper operation.
SLIPS
OUT OF
GEAR

Transmission disengagement may be caused by
misaligned or damaged shift components, or worn
teeth on the mainshaft gears or synchro components. Incorrect assembly will also contribute to gear disen­gagement.

LOW LUBRICANT LEWEL
Insufficient transmission lubricant is usually the
result of leaks, or inaccurate fluid level check or re­
fill method.
Leaks will be evident by the presence of gear oil
around the leak point. If leakage is not evident, the
condition is probably the result of an underfill condi­
tion.
If air powered lubrication equipment is used to fill
a transmission, be sure the equipment is properly
calibrated. Equipment out of calibration can lead to
an underfill condition.

CLUTCH
PROBLEMS
Worn, damaged, or misaligned clutch components
can cause difficult shifting, gear clash and noise.
A damaged pilot bearing will cause noise. If bear­
ing damage is severe, drive gear misalignment and
hard shifting can also occur.
A worn or damaged clutch disc, pressure plate, or
release bearing can cause hard shifting and gear clash.
Damaged or worn clutch hydraulic components, or
leaks in the fluid lines or cylinders will cause hard shifting and gear clash. Failure of one of the clutch
hydraulic cylinders can result in incomplete clutch release or engagement.
Verify that clutch components are all in good con­
dition before removing the transmission for repair.

TRANSMISSION
REMOVAL—2-WHEEL DRIVE
(1) Disconnect battery negative cable. (2) Shift transmission into Neutral.
(3) Remove screws attaching shift boot to floorpan.
Then slide boot upward on lever. (4) Loosen nut that secures shift lever on transmis­
sion stub lever. Then remove shift lever from stub le­
ver. (5) Raise and support vehicle.
(6) Mark propeller shaft and axle yokes for align­
ment reference. Use paint, scriber, or chalk to mark

yokes.
(7) Remove U-joint clamp strap screws and remove
clamps. (8) Remove propeller shaft.
(9) Disconnect and remove exhaust system Y-pipe.
(10) Disconnect wires at speed sensor and backup
light switch. (11) Support engine with adjustable safety stand
and wood block.

21
- 82
AUTOMATIC TRANSMISSION—32RH/36RH/37RH/42RH/46RH
————— •
PART
NUMBER BUILD
DATE SERIAL
NUMBER The fourth gear shift valves and plugs are located
in the valve body lower housing. The components in­
clude:
• a separate housing for the overdrive valves and
plugs • an overdrive solenoid
• a converter clutch solenoid
• a 3-4 shift valve
• a 3-4 timing valve
• a 3-4 accumulator • a 3-4 shuttle valve
• an overdrive separator plate. • a boost valve and connecting tube

J9121-202
FOURTH GEAR OVERDRIVE OPERATION Fig.
3
Identification
Number
And
Code
Location
overdrive unit. The intermediate shaft is supported
by the overdrive piston retainer and piloted in the output shaft.
The overdrive piston and retainer are located at
the rear of the transmission case. The retainer serves as both the rear support and pressure chamber for
the overdrive piston. The intermediate shaft is splined to the overdrive direct clutch sliding hub,
planetary assembly and overrunning clutch.
The governor components and speedometer drive
are located on the output shaft in the overdrive unit.
Two bearings are used to support the output shaft. A longer park rod assembly is also required.
There are no rotating seal rings or pressurized oil
for the direct clutch. The clutch is applied by spring
pressure and released by movement of the overdrive clutch piston during the 3-4 upshift.
The governor is operated by fluid pressure supplied
through pressure tubes. The tubes are permanently attached to the governor support. Governor fluid
pressure is transmitted through the intermediate shaft to the tubes.
Governor pressure and overdrive clutch pressure
taps are provided in the transmission case for pres­ sure testing purposes.
The overdrive unit contains a direct clutch, an
overdrive clutch and an overrunning clutch. Fourth
gear range is provided by an additional planetary
gear set In the overdrive unit.
The direct clutch is applied by spring pressure. A
high pressure spring rated at approximately 830
pounds (5530 kPa) tension, holds the clutch in en­ gagement. The sun gear, direct clutch sliding hub
and drum are splined to the annulus gear for direct
drive. For coasting or reverse gear, power flows only
through the direct clutch.
A timing valve disengages the torque converter
clutch prior to a 4-3 downshift. The clutch solenoid, engagement valve, and timing valve are actuated in
fourth gear range. 3-4
Shift
Sequence

The overdrive clutch is applied in fourth gear only.
The direct clutch is applied in all ranges except
fourth gear.
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 en­
ergized 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 switch must be in the On position to
transmit signals to the solenoid. A 3-4 upshift occurs only when the overdrive solenoid is energized by an electrical signal from the powertrain control module. The solenoid is energized upon receiving a signal.
This causes the check ball to close the vent port. Closing the vent port allows line pressure from the
2-3 shift valve to act directly upon the 3-4 upshift
valve.
Line pressure acting on the 3-4 shift valve over­
comes valve spring tension moving the valve to the
upshift position. This action exposes the feed pas­ sages to the 3-4 timing valve, 3-4 shuttle valve, 3-4 accumulator and ultimately to the overdrive piston.
Line pressure through the timing and shuttle
valves move the overdrive piston into simultaneous
contact with the overdrive clutch and the direct clutch sliding hub.
The overdrive clutch is engaged and the direct
clutch is disengaged simultaneously to complete the 3-4 upshift.
The boost valve provides increased fluid apply pres­
sure to the overdrive clutch during the 3-4 upshift and during fourth gear operation. The amount of
boost is determined by throttle opening and line pressure.
The overdrive piston engages the overdrive clutch
by pressing directly against the clutch pressure

•

AUTOMATIC TRANSiISSIO|-32RH/8iRH/37RH/42RH/4iRH
21 - 83 plate. The overdrive clutch also disengages the direct
clutch during 3-4 upshifts. As fluid pressure extends
the overdrive piston, the piston contacts the direct clutch hub pressing it rearward. This action com­
presses the direct clutch spring relieving spring load on the clutch pack. The clutch is disengaged once
spring load is relieved.
The 3-4 accumulator cushions overdrive clutch en­
gagement to smooth the transition into fourth gear.
The accumulator is charged at the same time as ap­
ply pressure acts against the overdrive piston.
Converter clutch engagement in overdrive fourth
gear is controlled by sensor inputs to the powertrain
control module. In third gear above 25 mph, sensor inputs to the control module that determine clutch
engagement and shift timing are:
• coolant temperature (verifies minimum of 60° F)
• engine speed • vehicle speed
• throttle position
• manifold vacuum (MAP sensor)

Gearshift
Mechanism
The gear shift mechanism provides the same shift
positions used with 3-speed Chrysler transmissions
(P-R-N-D-2-1).

The shift into overdrive fourth gear range occurs
only after the transmission has completed the shift into D third gear range. No further movement of the
shift mechanism is required to complete the 3-4 shift.
The fourth gear upshift occurs automatically when
the overdrive control switch is in the ON position. Shift timing is determined by sensor inputs to the
engine controller.
Overdrive Control
Switch
The overdrive control switch is located in the in­
strument panel. In the On position, automatic shifts
into fourth gear overdrive will occur. In the Off posi­
tion, the switch overrides the engine controller pre­
venting a shift to overdrive fourth gear range.
The switch has an indicator light that illuminates
when overdrive is turned off. The switch also resets
when the ignition key is turned to the OFF position so that the automatic overdrive feature is restored.
The use of fault codes is employed to help diagnose
the electronic components that operate the overdrive
unit and converter clutch.

HYDRAULIC
CONTROLS
The 42REJ/46RH hydraulic control system provides
fully automatic operation. The system performs five
basic functions which are: pressure supply, pressure regulation, flow control, clutch/band application, and
lubrication. 42RH/46RH system operation is similar to that de­
scribed in the 32RH/36RH/37RH General Informa­ tion section. The main difference being fourth gear
operation which is covered here.

Pressure
Regulation
The pressure regulator valve maintains line pres­

sure.
The amount of pressure developed is controlled
by throttle pressure which is dependent on the de­ gree of throttle opening. The regulator valve is lo­
cated in the valve body.
The throttle valve determines line pressure and
shift speed. Governor pressure increases in propor­
tion to vehicle speed. The throttle valve controls up­ shift and downshift speeds by regulating pressure
according to throttle position.

Flow
Control And Lubrication The manual valve is operated by the gearshift link­
age and provides the operating range selected by the
driver.
The 1-2 shift valve provides 1-2 or 2-1 shifts and
the 2-3 shift valve provides 2-3 or 3-2 shifts.
The kickdown valve provides forced 3-2 or 3-1
downshifts depending on vehicle speed. Downshifts
occur when the throttle is opened beyond downshift
detent position which is just before wide open throt­

tle.

The 2-3 valve throttle pressure plug provides 3-2
downshifts at varying throttle openings depending on
vehicle speed.
The 1-2 shift control valve transmits 1-2 shift pres­
sure to the accumulator piston. This controls kick-
down band capacity on 1-2 upshifts and 3-2 downshifts.
The 3-4 shift valve, shuttle valve, timing valve and
accumulator are only actuated when the overdrive
solenoid is energized.
The solenoid contains a check ball that controls a
vent port to the 3-4 valve. The check ball either di­
verts line pressure away from or directly to, the 3-4 shift valve. Energizing the solenoid causes the check
ball to close the vent port allowing line pressure to act upon the 3-4 upshift valve.
The limit valve determines maximum speed at
which a 3-2 part throttle kickdown can be made. Some transmissions do not have the limit valve and
maximum speed for a 3-2 kickdown is at the detent
position.
The 2-3 shuttle valve has two functions. First is
fast front band release and smooth engagement dur­ ing lift-foot 2-3 upshifts. The second is to regulate
front clutch and band application during 3-2 down­
shifts.
The 3-4 shuttle valve uses a combination of throt­
tle and governor pressure to control the rate of over­
drive piston apply and release. This is done to
maintain shift quality at varying throttle openings.

•

AUTOMATIC TRANSiISSiOi-32RH/38RH/37RH/42RH/4eRH
21 - 81 AUTOMATIC TRANSMISSION DIAGNOSIS AND TESTING

INDEX

page

Air Testing Clutch
and
Band Operation
91

Analyzing
the
Road Test
87
Converter Housing Fluid Leak Diagnosis
.......
92
Converter
Stall
Test
90
Diagnosis
Charts
and
Hydraulic Flow Diagrams
. . 95

Fluid Contamination
86

Fluid Level
and
Condition
85

GENERAL
INFORMATION
The diagnosis
and
testing information
in
this sec­
tion applies
to
three
and
four speed models alike.
Di­
agnosis
and
test procedures apply
to all
models
except where indicated. Diagnosis information that
only applies
to
42RH/46RH models
is
noted.
Automatic transmission problems
can be a
result
of

poor engine performance, incorrect fluid level, incor­
rect linkage adjustment, band
or
hydraulic control
pressure adjustments, hydraulic system malfunctions
or electrical/mechanical component malfunctions.
Begin diagnosis
by
checking
the
easily accessible
items such
as:
fluid level
and
condition, linkage
ad­

justments
and
electrical connections
on
4-speed mod­
els.
A
road test will determine
if
further diagnosis
is
necessary. Procedures outlined
in
this section should
be
per­
formed
in the
following sequence
to
realize
the
most accurate results:
• Preliminary diagnosis
• Fluid Level
and
condition • Linkage Adjustment
• Road test
• Hydraulic pressure test • Stall test
•
Air
pressure tests
• Leak Tests
• Analyze test results
and
consult diagnosis charts

PRELIMINARY
DIAGNOSIS
Two basic procedures
are
required.
One
procedure
for vehicles that
are
driveable
and an
alternate pro­ cedure
for
disabled vehicles (will
not
back
up or

move forward).

Vehicle
Is
Driveable
(1) Check fluid level
and
condition.
(2) Adjust throttle
and
gearshift linkage
if
com­
plaint
was
based
on
delayed, erratic,
or
harsh shifts.
(3)
On
4-speed models, check electrical connections
at dash switch
and
transmission case. Turn control
switch
to ON
position before proceeding. (4) Road test
and
note transmission operating
characteristics.
page

Gearshift Linkage
87

General
Information
85

Hydraulic Pressure Test
88

Overdrive Fourth Gear
Electrical
Controls
......
86
Preliminary Diagnosis
85

Road
Test
87

Throttle
Valve Cable
86

(a)
If
acceleration
is
sluggish,
or if
abnormal
throttle opening
is
needed
to
maintain normal speeds with
a
properly tuned engine, perform
a

stall test
to
check converter clutch operation. (b)
On
42RH/46RH,
if
fourth gear upshift does
not occur, check overdrive solenoid
and
switch wir­ ing
for
opens, shorts, grounds.
(c)
If
slippage
and
engine flare
is
noted, perform
hydraulic pressure test
and air
pressure test
to
check clutch-band-governor operation.

Vehicle
Is
Disabled
(1) Check fluid level
and
condition.
(2) Check
for
broken, disconnected throttle link­

age.

(3) Check
for
cracked, leaking cooler lines,
or

loose, missing pressure port plugs.
(4) Raise vehicle, start engine, shift transmission
into gear
and
note following:
(a)
If
propeller shafts turn
but
wheels
do not,

problem
is
with differential
or
axle shafts. (b)
If
propeller shafts
do 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 shafts
do not
turn
and
transmis­
sion
is not

noisy, perform hydraulic pressure test
to
deter­
mine
if
problem
is a
hydraulic
or
mechanical.

FLUID LEVEL AND CONDITION
(1) Place vehicle
on
level surface. This
is
impor­
tant
for an
accurate reading. (2)
Do not
check level until fluid
is at
normal
op­

erating temperature
of
approximately 82°C (180°F).
This
is
necessary
to
avoid false readings which could
produce under
or
over fill condition, (3) Fully apply parking brakes.
(4) Start
and run
engine
at
curb idle speed. Then
shift transmission through
all
gear ranges
and
back
to Neutral. (5) Clean
top of
filler tube
and
dipstick
to
keep dirt
out
of
tube.

21 - 86
AUTOMATIC
TRANSMISSION-32RH/36RH/37RH/42RH/46RH

•
(6)
Remove dipstick and check fluid
level
as fol­

lows:

(a) Dipstick has three fluid level indicating
marks which are a MIN dot mark, an OK mark and a MAX fill arrow mark:
(b) Correct level is to MAX arrow nark on dip­
stick. This is correct maximum hot fluid level. Ac­
ceptable level is between OK mark and max arrow
mark on dipstick.
(c) If level is at, or below MIN level dot on dip­
stick, add only enough fluid to restore correct level.
Mopar ATF Plus, type 7176 is the preferred fluid.
Mopar Dexron II can be used if ATF Plus is not
readily available.

CAUTION:
Do not
overfill
the
transmission.
Overfill­
ing
may
cause
leakage out the
pump
vent which

can
be mistaken for a
pump
seal
leak. In addition,

overfilling
will
also
cause
fluid
aeration
and
foam­
ing
as the
excess
fluid is picked up and churned by
the
gear
train.
This
will
significantly
reduce fluid
life.

(7) Check and note fluid condition as follows: (a) Fluid should be dark to light red in color and
free of particles and sludge.
(b) If fluid is orange, brown, or smells slightly
burned, flow test and reverse flush cooler and lines. Then change fluid and filter and road test again to
confirm proper operation.
(c) If fluid is black, dark brown, turned to sludge,
contains extensive amount of metal or friction ma­
terial particles, transmission will need overhaul. Main and auxiliary coolers will have to be flow
tested and reverse flushed as well.

Effects
Of Incorrect Fluid Level A low fluid level allows the pump to take in air
along with the fluid. Air in the fluid will cause fluid
pressures to be low and develop slower than normal.
If the transmission is overfilled, the gears churn
the fluid into foam, aerating the fluid and causing
the same conditions that occur with a low level.
In either case, air bubbles cause fluid overheating,
oxidation and varnish buildup which interferes with
valve, clutch and servo operation. Foaming also causes fluid expansion which can result in fluid over­
flow from the transmission vent or fill tube. Fluid
overflow can easily be mistaken for a leak if inspec­
tion is not careful.

FLUID
CONTAMINATION
Transmission fluid contamination is generally a re­
sult of:
• adding incorrect fluid
• failure to clean dipstick and fill tube when check­ ing level
• engine coolant entering the fluid • internal failure that generates debris
• overheat that generates sludge (fluid breakdown)
• failure to reverse flush cooler and lines after re­
pair
• failure to replace contaminated converter after re­
pair
The use of non recommended fluids can result in
transmission failure. The usual results are erratic
shifts,
slippage, abnormal wear and eventual failure
due to fluid breakdown and sludge formation. Avoid
this condition by using recommended fluids only.
The dipstick cap and fill tube should be wiped
clean before checking fluid level. Dirt, grease and
other foreign material on the cap and tube could fall
into the tube if not removed beforehand. Take the
time to wipe the cap and tube clean before withdraw­ ing the dipstick.
Engine coolant in the transmission fluid is gener­
ally caused by a cooler malfunction. The only remedy
is to replace the radiator as the cooler in the radiator
is not a serviceable part. If coolant has circulated
through the transmission for some time, an overhaul may also be necessary; especially if shift problems
had developed.
The transmission cooler and lines should be reverse
flushed whenever a malfunction generates sludge and/or debris. The torque converter should also be re­
placed at the same time.
Failure to flush the cooler and lines will result in
re-contamination and a shop comeback. Flushing ap­
plies to auxiliary coolers as well. The torque con­ verter should also be replaced whenever a failure
generates sludge and debris. This is necessary be­
cause normal converter flushing procedures will not
remove al of the contaminants.

OVERDRIVE
FOURTH
GEAR
ELECTRICAL

CONTROLS
The electrical controls governing the shift into
fourth gear consist of the control switch on the in­ strument panel and the overdrive solenoid on the
valve body. The control switch is in circuit with the solenoid and must be in the On position to energize
the solenoid. The transmission must also have
reached third gear range before the shift to fourth gear will occur. The control switch, valve body solenoid, case con­
nectors and related wiring can all be tested with a 12
volt test lamp or a multimeter. Check continuity of each component when diagnosis indicates this is nec­
essary. Switch and solejioid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.

THROTTLE
VALVE
CABLE

Throttle valve cable adjustment is important to
proper operation. This adjustment positions the

AUTOMATIC TRANSMISSION—32RH/36RH/37RH/42RH/46RH
21 - 87
throttle valve which controls shift speed, quality and
part throttle downshift sensitivity. If cable setting is too short, early shifts and slip­
page between shifts may occur. If the setting is too long, shifts may be delayed and part throttle down­shifts may be very sensitive. Refer to the In-Vehicle
Service section for adjustment procedure.

GEARSHIFT LINKAGE
Gearshift linkage adjustment is important because
it positions the valve body manual valve. Incorrect
adjustment will cause creeping in Neutral, prema­
ture clutch wear, delayed engagement in any gear, or a no-start in Park or Neutral position.
Proper operation of the neutral start switch will
provide a quick check of linkage adjustment. Refer to
the In-Vehicle Service section for adjustment proce­
dure.

ROAD TEST
Before road testing, be sure the fluid level and all
linkage adjustments have been checked and adjusted
if necessary. Observe engine performance during the road test.
A poorly tuned engine will not allow an accurate analysis of transmission operation. Operate the transmission in all gear ranges. Check
for slippage and shift variations. Note whether the shifts are harsh, spongy, delayed, early, or if part
throttle downshifts are sensitive. Watch closely for slippage or engine flare which
usually indicates clutch, band or overrunning clutch
problems. If the condition is advanced, an overhaul
may 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. Refer to the Elements In Use Charts (Figs. 1 and 2) for clutch and band applica­
tion. The charts provide a basis for analyzing road
test results.

ANALYZING
THE
ROAD TEST
Refer to the Clutch And Band Application charts

(Figs.
1 and 2). Then note which elements are ap­
plied in the various gear ranges. The rear clutch is applied in all forward ranges (D,

2,
1). The transmission overrunning clutch is applied
in first gear (D, 2 and 1 ranges only). The rear band is applied in 1 and R range only.
The overdrive clutch is applied only in fourth gear and the overdrive direct clutch and overrunning
clutch are applied in all ranges except fourth gear. For example: If slippage occurs in first gear in D
and 2 range but not in 1 range, the transmission
overrunning clutch is slipping. Similarly, if slippage
occurs in third and fourth gear, the rear clutch is
slipping. However, if slippage only occurs in fourth gear, the overdrive clutch is slipping.
Gearshift
Lever
Position
DRIVE
ELEMENTS P

R
N
D 2 1

DRIVE
ELEMENTS
1 2 3 1
2

FRONT
CLUTCH
•
•

FRONT BAND
(KICKDOWN)
•
•

REAR

CLUTCH

REAR

BAND
(LOW-REV.)
•
•

OVER­
RUNNING CLUTCH
•
• •
J9021-33
Fig.
1
Clutch
And
Band
Application—32RH/36RH/

37RH

Applying the same method of analysis, note that
both clutches are applied in D range third gear only. If the transmission slips in third gear, either the
front clutch or the rear clutch is slipping. By selecting another gear which does not use both
clutches, the slipping clutch can be determined. For example, if the transmission also slips in Reverse,
the front clutch is slipping. If the transmission does not slip in Reverse, the rear clutch is slipping.
If slippage occurs during the 3-4 shift or in fourth
gear, the overdrive clutch is slipping. Similarly, if
the direct clutch were to fail, the transmission would lose reverse gear and overrun braking in 2 (manual second gear) position would not occur. If the trans­
mission slips in any other two forward gears, the
transmission front section rear clutch may be slip­
ping.
If the transmission will not shift into fourth gear,
the control switch, overdrive solenoid or related wir­
ing may also be the problem cause.
This process of elimination can be used to deter­
mine the slipping unit and check operation. Proper use of the Clutch and Band Application Chart is the
key.
Although road test analysis will help determine
the slipping unit, the actual cause of a malfunction usually cannot be determined until hydraulic and air
pressure tests are performed. Practically any condi­ tion can be caused by leaking hydraulic circuits or sticking valves.
Unless the condition is obvious, such as no
drive in D range, first gear only, or no fourth
gear range, the transmission should not be dis­
assembled until hydraulic and air pressure tests
have been performed.

21 - 90
AUTOMATIC
TRANSMISSION—32RH/36RH/37RH/42RH/46RH

• (4) Note pressure with engine at curb idle speed
and rear wheels stopped. Pressure should be zero to 1-1/2 psi maximum. If pressure exceeds this figure,
governor valve or weights are sticking open.
(5) Slowly increase engine rpm and observe speed­
ometer and pressure test gauge. Governor pressure should increase in proportion to indicated vehicle
speed (or approximately 1 psi for every 1 mph).
(6) Pressure rise should be smooth and drop back
to 0 to 1-1/2 psi when wheels are braked to a stop and engine returns to curb idle speed.
(7) Compare results of the pressure tests with the
Pressure Test Analysis Charts (Figs. 6 and 7).

Test
Six—42RH/46RH
Transmission
In Overdrive Fourth
Gear

This test checks line pressure at the overdrive
clutch in fourth gear range. Use 300 psi Test
Gauge C-3292 for this test.
(1) Raise vehicle and connect test gauge to over­
drive clutch pressure port (Fig. 5). (2) Lower vehicle to enough to allow entry into
drivers seat. Leave vehicle wheels approximately one
foot off shop floor.
(3) Secure test gauge where it can be viewed from
drivers seat.
(4) Verify that overdrive control switch is in ON
position. (5) Start engine and shift into D range.
(6) Increase engine rpm gradually until 3-4 shift
occurs and note gauge pressure. (7) Pressure should be 469-496 kPa (68-72 psi)
with closed throttle and increase to 620-827 kPa (90- 120 psi) at 1/2 to 3/4 throttle. Note that pressure will
increase to 896 kPa (130 psi) or more at full throttle. (8) Refer to pressure test chart (Fig. 7) for pressure
diagnosis.

CONVERTER
STALL
TEST
Stall testing involves determining maximum en­
gine rpm obtainable at full throttle with the rear
wheels locked and the transmission in D range. This
test checks the holding ability of the converter over­
running clutch and both of the transmission clutches. When stall testing is completed, refer to the Stall
Speed Specifications chart and Stall Speed Diagnosis
guides.

WARNING:
NEVER
ALLOW
ANYONE
TO
STAND

IN
FRONT
OF THE
VEHICLE
DURING
A
STALL

TEST.
ALWAYS
BLOCK
THE
FRONT
WHEELS
AND
APPLY
THE
SERVICE
AND
PARKING
BRAKES
DURING
THE
TEST.

STALL
TEST
PROCEDURE
(1) Connect tachometer to engine.
(2) Check and adjust transmission fluid level.
1EST
CONDITION
INDICATION

Line
pressure
OK during

any
one test
Pump
and regulator valve OK

Line
Pressure
OK in R
but low in D, 2, 1
Leakage
in
rear
dutch area
(servo,

dutch
seals,
governor
support

seal
rings)

Pressure
OK in 1, 2 but

low
in D3 and R
Leakage
in
front
dutch area
(servo,

dutch
seals,
retainer
bore,
pump
seal
rings)

Pressure
OK in 2 but low in

R
and 1
Leakage
in
rear
servo

Front
servo
pressure
in 2
Leakage
in
servo;
broken
servo

ring
or
cracked
servo
piston

Pressure
low in all
positions
Cogged
filter,
stuck
pressure

regulator valve, worn or
defective
pump

Governor
pressure
too
high
at idle
speed:
Governor
valve
sticking
open

Governor
pressure
low at all
mph
figures
Governor
valve
sticking
dosed

Lubrication
pressure
low at all

throttle
positions
Clogged
oil cooler or
lines,
seal

rings
leaking,
output shaft

plugged
with
debris,
worn

bushings
in
pump
or dutch

retainer
J9021-34

Fig.
6
Pressure
Test
Analysis
Chart (32RH/36RH/
37RH)

(3) Start and run engine until transmission fluid
reaches normal operating temperature. (4) Block front wheels.
(5) Fully apply service and parking brakes.
(6) Open throttle completely for no more than five
seconds and record maximum engine rpm registered
on tachometer.

CAUTION:
Stall testing
causes
a rapid increase in

transmission
fluid
temperature. Do not
hold
the

throttle
open
any
longer
than
five
seconds.
If more
than one stall test is required, run the engine at 1000 rpm
with
the
transmission
in Neutral for at

least
20
seconds
to
cool
the fluid.
(7) If engine speed exceeds maximum shown in
stall speed chart, release accelerator pedal immedi­
ately. This condition indicates transmission clutch
slippage is occurring.
(8) Shift transmission into Neutral. Operate en­
gine for 20 seconds. Stop engine, shift transmission
into Park and release brakes.
(9) Stall speeds should be: 1800-2100 rpm with
3.9L engine and 1700-2000 rpm with 5.2L/5.9L en­

gines.

(10) Refer to Stall Test Diagnosis.

AUTOMATIC
TRANSMISSION—32RH/36RH/37RH/42RH/46RH
21 - 91

TEST
CONDITION

Line pressure OK during
any one test
Line Pressure OK in
R

but low in D, 2, 1
Pressure Low in D
Fourth Gear Range
Pressure OK in 1, 2 but
low
in
D3
and
R

Pressure OK in 2 but low in
R
and 1
Front servo pressure low
in 2
Pressure low in all positions
Governor pressure too high
at idle speed
Governor pressure low
at all mph figures Lubrication pressure low at
all throttle positions
INDICATION

Pump and regulator valve OK
Leakage in rear clutch area (servo,
clutch seals, governor support seal rings)
Overdrive clutch piston seal, or
check ball problem
Leakage in front clutch area (servo,
clutch seals, retainer bore, pump seal rings)
Leakage in rear servo
Leakage in servo; broken servo
ring or cracked servo piston
Clogged filter, stuck regulator
valve, worn or faulty pump, plugged fluid cooler
Governor valve sticking open
Governor valve sticking closed
Clogged oil cooler or lines, seal rings leaking, output shaft plugged
with debris, worn bushings in pump or clutch retainer

J9321-165
Fig.
7
Pressure
Test
Analysis
Chart (42RH/46RH)

STALL
TEST
DIAGNOSIS

Stall
Speed
Too
High
If stall speed exceeds specifications by more than
200 rpm, transmission clutch slippage is indicated.

Stall
Speed
Too Low Low stall speeds with a properly tuned engine in­
dicate a torque converter overrunning clutch prob­
lem. The condition should be confirmed by road
testing prior to converter replacement. The converter overrunning clutch is slipping when:
Stall speeds are 250 to 350 rpm below specified min­
imum and the vehicle operates properly at highway
speeds but has poor low speed acceleration.

Stall
Speed
Normal
If stall speeds are normal but abnormal throttle
opening is required to maintain highway speeds, the
converter overrunning clutch is seized and the torque
converter must be replaced.

Converter
Noise
During
Test
A whining noise caused by fluid flow is normal
during a stall test. However, loud metallic noises in­ dicate a damaged converter. To confirm that noise is
originating from the converter, operate the vehicle at
light throttle in Drive and Neutral on a hoist and
lis­

ten for noise coming from the converter housing.

AIR
TESTING
CLUTCH
AND
BAND
OPERATION
Air pressure testing can be used to check clutch
and band operation with the transmission either in
the vehicle, or on the work bench as a final check af­
ter overhaul. Air pressure testing requires that the oil pan and
valve body be removed from the transmission. The servo and clutch apply passages are shown in Figure
8.
FRONT
SERVO
APPLY^

REAR
SERVO
APPLY

LINE
PRESSURE
TO
ACCUMULATOR

GOVERNOR
PRESSURE
FRONT

SERVO

RELEASE

PUMP

SUCTION

PUMP

PRESSURE

FRONT

CLUTCH
APPLY

REAR

CLUTCH
APPLY

TO
TORQUE

CONVERTOR

I

FROM
TORQUE
CONVERTER

TO

GOVERNOR
TO
COOLER
^H252

Fig.
8 Air
Pressure
Test
Passages
Front
Clutch
Test

Place one or two fingers on the clutch housing and
apply air pressure through front clutch apply passage (Fig. 8). Piston movement can be felt and a soft thud
heard as the clutch applies.

Rear
Clutch
Test
Place one or two fingers on the clutch housing and
apply air pressure through rear clutch apply passage
(Fig. 8). Piston movement can be felt and a soft thud
heard as the clutch applies.

Front
Servo
Test
Apply air pressure to the front servo apply passage.
The servo rod should extend and cause the band to
tighten around the drum. Spring tension should re­ lease the servo when air pressure is removed.