1993 DODGE TRUCK Service Repair Manual

21 - 88
AUTOMATIC
TRANSMISSION—32RH/36RH/37RH/42RH/46RH
•

SHIFT

LEVER

POSITION
TRANSMISSION
CLUTCH

ES
AND
BANDS
OVERDRIVE
CLUTCHES
SHIFT

LEVER

POSITION FRONT
CLUTCH FRONT

BAND
REAR

CLUTCH
REAR

BAND
OVERRUN.

CLUTCH
OVERDRIVE

CLUTCH DIRECT
CLUTCH
OVERRUN.

CLUTCH

Reverse
X X
X

Drive
Range
First

Second

Third
Fourth
X
X X
X X
X X
X X
X
X X
X
X

2-Range:
(Manual

Second):
Second

First
X
X
X X X
X
X
X

1-Range
(Manual

Low):
First
X X X X
X

J9221-22
Fig.
2
Clutch
And
Band
Application-42RH/46RH
HYDRAULIC PRESSURE
TEST
«\ \\\REAR
\\v
-
LINE
FRONT
' M
SERVO
\\ PRESSURE
/S—'
SERVO

PRESSURE
TEST
PORT
LOCATIONS
\\\
W \\\ PO.RT, \ i PORT

There are pressure test ports at the accumulator,
front servo, rear servo and governor. On 42RH/46RH
transmissions, an additional port for overdrive clutch
pressure is provided at the left-rear of the case. Line pressure is checked at the accumulator port
on the right side of the case (Fig. 3). The front servo
pressure port is at the right side of the case just be­
hind the filler tube opening (Fig. 4). The rear servo pressure port is at the right rear of
the case (Fig. 3). The governor pressure port is at the left side of the extension housing (Fig. 4). On 42RH/46RH transmissions, the governor and
overdrive clutch pressure ports are at the rear of the
case (Fig. 5). Hydraulic test pressures range from a low of one
psi (6.895 kPa) governor pressure, to 300 psi (2068
kPa) at the rear servo pressure port in reverse. Two gauges are needed for the pressure test. Use
Pressure Gauge C-3292 to check pressure at the ac­
cumulator, front servo, governor and overdrive pres­
sure ports. Use 300 psi Pressure Gauge C-3293 to check pressure at the rear servo. The 300 psi gauge
can also be used to check all other pressures except
governor pressure.

PRESSURE
TEST
PROCEDURE
Connect a tachometer to the engine. Position the
tachometer so it can be observed from under the ve­
hicle. Raise the vehicle on hoist that will allow the wheels to rotate freely.

F
Fig.
3
Pressure
Test Ports At
Side
Of
Case

GOVERNOR

PRESSURE
PORT

Fig.
4
Pressure
Test Ports At Rear Of
Case

Test
One—Transmission
In 1
Range
This test checks pump output, pressure regula­

tion,
and condition of the rear clutch and rear servo circuits. Pressure Gauges C-3292 and C-3293 are required for this test.
(1) Connect 100 psi Gauge C-3292 to accumulator
(line pressure) port and connect 300 psi Gauge

•

AUTOMATIC
TRANSMISSION—32RH/36RH/37RH/42RH/46RH
21 - 89

Fig.
5
Pressure
Test Port
Locations—42RH/46RH
C-3293 to rear servo port (Figs. 3, 4). Be sure 300
psi gauge is connected to rear servo port.
(2) Disconnect throttle and gearshift cable/linkage
at transmission. (3) Start and run engine at 1000 rpm.
(4) Move transmission shift lever (on valve body
manual shaft) all way forward into 1 range.
(5) Read pressures on both gauges as transmission
throttle lever is moved from full forward to full rear­
ward position.
(6) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in­
crease to 90-96 psi (621-662 kPa) as lever is moved
rearward.
(7) Rear servo pressure should be same as line
pressure within 3 psi.

Test
Two—Transmission
In 2
Range

This test checks pump output and pressure
regulation. Use 100 psi Gauge C-3292 for this test. (1) Connect pressure gauge to accumulator (line
pressure) port (Fig. 3).
(2) Start and run engine at 1000 rpm.
(3) Move transmission shift lever (on valve body
manual shaft) one detent rearward from full forward
position. This is 2 range. (4) Move transmission throttle lever from full for­
ward to full rearward position and read pressure at
both gauges.
(5) Line pressure should be 54-60 psi 372-414 kPa)
with throttle lever forward and gradually increase to 90-96 psi ( 621-662 kPa) as lever is moved rearward.

Test
Three—Transmission
In D
Range
This test checks pressure regulation and con­
dition of the front and rear clutch circuits. Use
both pressure gauges for this test.
(1) Connect gauges to accumulator (line pressure)
and front servo ports (Fig. 3). Either pressure test
gauge can be used at either port.
(2) Start and run engine at 1600 rpm for this test.
(3) Move selector lever two detents rearward from
full forward position. This is D range.
(4) Read pressures on both gauges as transmission
throttle lever is moved from full forward to full rear­
ward position.
(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in­ crease as lever is moved rearward. (6) Front servo is pressurized only in D range and
should be same as line pressure within 3 psi (21 kPa)
up to downshift point.

Test
Four—Transmission
In
Reverse
This test checks pump output, pressure regula­
tion and the front clutch and rear servo circuits.
Use 300 psi Gauge C-3293 for this test.
(1) Connect pressure gauge to rear servo port

(Figs.
3 and 4). (2) Start and run engine at 1600 rpm for test. (3) Move valve body selector lever four detents
rearward from full forward position. This is Reverse
range.
(4) Move throttle lever fully forward then fully
rearward and note gauge readings.
(5) Pressure should be 145 - 175 psi (1000-1207
kPa) with lever forward and increase to 230 - 280 psi (1586-1931 kPa) as lever is moved rearward.

Test
Five—Governor
Pressure
This test checks governor operation by mea­
suring governor pressure response to changes in
engine speed. It is usually not necessary to check governor operation unless shift speeds
are incorrect or if the transmission will not
downshift. Use 100 psi Gauge C-3293 for this
test.
(1) Position vehicle on hoist that will allow rear
wheels to rotate freely.
(2) Connect pressure gauge to governor pressure
port (Figs. 4 and 5). (3) Start engine, shift the transmission into drive
(D) range and apply brakes to prevent rear wheels
from rotating.

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.

21
- 12
AUTOMATIC TRANSMISSION—32RH/36RH/37RH/42RH/46RH

•
Rear Servo
Test
Apply air pressure to the rear 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.

CONVERTER
HOUSING
FLUID
LEAK
DIAGNOSIS
When diagnosing converter housing fluid leaks,
two items must be established before repair. First, it must be verified that a leak condition actually exists.
And second, the true source of the leak must be de­
termined. Some suspected converter housing leaks may not
be leaks at all. They may only be the result of resid­ ual fluid in the converter housing, or excess fluid spilled during factory fill or refill after repair. Converter housing leaks have several potential
sources. Through careful observation, a leak source
can be identified before removing the transmission
for repair. Pump seal leaks tend to move along the drive hub
and onto the rear of the converter. Pump O-ring or
pump body leaks follow the same path as a seal leak (Fig. 9). Pump vent or pump attaching bolt leaks are gener­
ally deposited on the inside of the converter housing
and not on the converter itself (Fig. 9). Pump seal or gasket leaks usually travel down the
inside of the converter housing. Front band lever pin plug leaks are generally de­
posited on the housing and not on the converter.
,j PUMP PUMP PUMP
Fig. 9 Typical Converter Homing Leak Paths
LEAK DIAGNOSIS PROCEDURE (1) Raise rear of vehicle and allow accumulated
fluid to drain out of converter housing.
(2) Check and adjust transmission fluid level.

(3)
Raise vehicle. Remove converter housing dust
cover and wipe as much fluid as possible from con­
verter housing.
(4) Fabricate test probe from steel or aluminum
stock (Fig. 10). Then attach probe to converter hous­ ing with one a dust shield bolt.

(5)
Have helper run engine at 2500 rpm (with
transmission in Neutral) for two minutes; then stop engine. (6) Inspect test probe and converter housing. If
leak is evident, note color of fluid. Transmission fluid
is red. Engine oil ranges in color from brown to
green, or to black when oil is dirty.
(7) If probe upper surface is dry, converter and seal
are OK. However, path of fluid across probe upper
surface indicates converter or seal leak. Fluid leak­
ing under probe is coming from pump housing area (Fig. 11).
(8) Fluid leaking under probe could be from: pump
seal and/or bushing, pump vent, kickdown lever shaft
access plug, pump bolts, or porous spots in pump
body or transmission case (Fig. 11).
(9) If porous spots in transmission case or pump
body are suspected leak source, pressurize transmis­ sion as described in Leak Testing With Air Pressure.
TORQUE CONVERTER LEAK POINTS

SHIELD
MATERIAL:
5-1/2"
X 1-1/2" X 1/32"
BOLT
SHEET
METAL
RN778
Fig.
10 Leak Test Probe
Fig.
11
Pump
Area
Inspection
Points

Possible sources of converter leaks are:

•

AUTOMATIC
TRANSMISSION-32RH/3IRH/37RH/42RH/48RH
21 - 13 • Leaks at weld joint around outside diameter weld
(Fig. 12).
• Leaks at converter hub weld (Fig. 12).

OUTSIDE
DIAMETER
WELD
TORQUE CONVERTER
HUB WELD
"LUG
STARTER RING GEAR
RH254

Fig.
12 Typical Converter
Leak
Points

LEAK
TESTING
WITH AIR
PRESSURE
This test involves closing off the transmission
openings and pressurizing the transmission to 8 psi (55 kPa) with air pump tool 7700.
A soapy water solution is applied to suspected leak
points before and during the pressure test. Leaks will
be indicated by the presence of air bubbles coming
through the solution.
Some transmission openings such as the fill tube
and front cooler line fitting can be closed off with a
rubber plug or similar device. Plugs can secured with
wire or duct tape.
The transmission rear output shaft opening is
closed off simply by leaving the transfer case bolted
in place. However, if the transfer case has been re­
moved, a shipping plug can used to close off this
opening. The torque converter hub opening in the pump and
the pump vent require special tools to close them off.
The converter hub seal cup is made from thin wall
tube and a 3.18 mm (1/8 in.) thick disc (Figs. 13, 14).
A retaining strap is needed to secure the seal cup
for testing. The strap can be made from 31.75 mm (1- 1/4 in.) wide stock (Fig. 15).
WELD OR

BRAZE
BREAK
EDGE

1/16"

MIN.

MATERIAL: 1-7/8 INCH O.D.
THIN
WALLED STEEL TUBING
AND 1/8 INCH STEEL DISC OUTSIDE OF OPEN
END FOR THIS
DISTANCE ON TUBE

RN779 The strap attaching hole positions are approximate
only. Measure hole position on the converter housing
before drilling.
The pump vent tool is made from 6.35 mm (1/4 in.)
rod and 4.75 mm (3/16 in.) plate (Figs. 16, 17). The fabricated tools can all be made from mild
steel or aluminum stock. WELD
OR BRAZE BREAK EDGE 1/16" MIN.

-«-l/8"

• SEAL THIS END AIR TIGHT

1-3/4"-*-

•
5"-
MATERIAL: 1-1/2 INCH O.D. THIN WALLED STEEL TUBING AND 1/8 INCH STEEL DISC POLISH
OUTSIDE
„OF OPEN

"END
FOR
THIS DISTANCE
ON TUBE
RN780
Fig.
14 Converter Hub
Seal
Cup-32RH/42RH

15/32 INCH DRILL 4 HOLES
MATERIAL: 1/4 INCH STEEL STOCK 1-1/4 INCH WIDE RN781
Fig.
13 Converter Hub
Seal
Cup-36RH/46RH
Fig.
15
Seal
Cup Retaining Strap

AIR
PRESSURE
LEAK
TEST
PROCEDURE
(1) Install vent plug, converter hub seal cup and
cup retaining strap (Fig. 18).
(2) Close off remaining transmission openings with
rubber plugs, or stoppers. Do not close off rear cooler line fitting as air pump will be attached
to this fitting.
(3) Attach Air Pump 7700 to rear cooler line fit­
ting. Connect length of copper tube to fitting. Then attach air pump hose to tube with hose clamp (Fig.
19).

(4) Apply thick soapy water solution to suspected
leak areas.

CAUTION:
The
recommended
test
pressure
is 8
psi.
The
maximum
allowable
test
pressure
is 10 psi
(68.9 kPa).
Do not
exceed
specified
pressure.

(5) Pressurize transmission to 8 psi (55 kPa) with
the hand operated air pump.

21
- 14
AUTOMATIC TRANSMISSION—32RH/36RH/37RH/42RH/46RH

•

MATERIAL:
3/16
INCH
STEEL
STOCK
Fig. 16 Pump Vent Piug-36RH/46RH

13/32" DRILL
2
HOLES MATERIAL:
3/16
INCH
STEEL
STOCK
KN/aj
Fig. 17 Pump Vent Plug-32RH/42RH
(6) Observe suspected leak areas. Air bubbles ap­
pearing in soapy water solution indicate leak points.
(7) Remove test tools and plugs after test comple­
tion and make necessary repairs. Refer to Converter Housing Area Leak Correction procedure.

CONVERTER HOUSING AREA LEAK
CORRECTION
(1) Remove transmission and remove torque con­
verter.
(2) Tighten front band adjusting screw until band
is tight around front clutch retainer. This prevents
front clutch from coming out when oil pump is re­
moved.
(3) Remove oil pump and seal. Inspect pump hous­
ing drainback and vent holes for obstructions. Clear
holes with solvent and wire.
COOLER
LINE
FITTING
RY254
Fig. 19 Pressurizing Transmission (4) Inspect pump bushing and converter hub. If
bushing is scored, replace it. If converter hub is scored, either polish it with crocus cloth or replace
converter if scoring is severe.
(5) Install new pump seal, O-ring, gasket, and
bushing. Replace oil pump if housing is cracked, po­
rous or damaged in any way.

(6)
Remove kickdown lever pin access plug. Apply
Mopar silicone sealer, or Permatex No. 2 to plug
threads and tighten plug to 17 N*m (150 in. lbs.) torque.
(7) Adjust front (kickdown) band.
(8) Lubricate pump seal and converter hub with
transmission fluid or petroleum jelly and install con­
verter.
(9) Install transmission.
(10) Install converter housing dust shield
(11) Lower vehicle and refill transmission with
recommended fluid.

•

AUTOMATIC
TRANSMISSION—32RH/36RH/37RH/42RH/46RH
21 - ii
DIAGNOSIS
CHARTS AND HYDRAULIC
FLOW

DIAGRAMS

The diagnosis charts and hydraulic flow diagrams
provide additional reference for transmission diagno­
sis.
The diagnosis charts provide general information
on a variety of transmission, overdrive unit and con­
verter clutch fault conditions. The Transmission Unit diagnosis charts apply to all transmission models.
The Overdrive Unit charts apply to the four speed
transmissions only.
The hydraulic flow diagrams outline transmission
fluid flow and hydraulic circuitry. The flow diagrams also provide basic working pressures for the various
gear ranges.