ESP JEEP CHEROKEE 1994 Service Workshop Manual

(10) Press 3-4 hub and sleeve off output shaft as
assembly (Fig. 63).
(11) Remove synchro ring.
(12) Remove third gear and needle bearing (Fig. 63).
TRANSMISSION CLEANING AND INSPECTION
Clean the transmission components in solvent. Dry
the cases, gears, shift mechanism and shafts with com-
pressed air.Dry the bearings with clean, dry shop
towels only. Never use compressed air on the bear-
ings. This could damage the bearing rollers.
Replace components that are obviously worn,
cracked, chipped or damaged in any way.
Inspect the transmission case. Replace the case if
cracked or porous or if any of the bearing and gear
bores are damaged.
Output Shaft Inspection
Measure thickness of the output shaft flange with
a micrometer (Fig. 64). Minimum allowable flange
thickness is 4.70 mm (0.185 in).
If shaft flange thickness is OK but previously
measured second/third gear thrust clearance
was incorrect (Fig. 62), replace the necessary
gear and needle bearing as an assembly.
Check diameter of the first, second and third gear
bearing surfaces of the output shaft (Fig. 64). Mini-
mum allowable diameters are:
²38.86 mm (1.529 in.) for first gear surface
²46.86 mm (1.844 in.) for second gear surface
²37.86 mm (1.490 in.) for third gear surface
Check output shaft runout with V-blocks and a dial
indicator (Fig. 64). Maximum allowable runout is
0.06 mm (0.0024 in.).
Replace the output shaft if any surface measured
fails to meet stated tolerance.
Cluster Gear Inspection
Inspect the cluster gear teeth. Replace the gear if
any teeth are worn or damaged or if the bearing sur-
faces are damaged.
Check diameter of the cluster gear journal with a
micrometer (Fig. 65). Minimum allowable diameter
is 27.860 mm (1.096 in.).
Check condition of the cluster gear front bearing.
Replace the bearing if worn, noisy, or damaged.
GEAR AND SYNCHRO INSPECTION
Install the synchro rings on their respective gears.
Rotate each ring on the gear and note synchro ac-
tion. Replace any synchro ring that exhibits a lack of
braking action or binds on the gear. Also replace any
ring that is worn or has chipped or broken teeth.
Measure end clearance between the synchro ring
and the gear with a feeler gauge (Fig. 66). Clearance
should be 0.06 mm - 1.6 mm (0.024 - 0.063 in.).Install the needle bearings in the first, second and
third gears. Then install the gears on the output
shaft and check shaft-to-gear clearance with a dial
indicator (Fig. 67).
Fig. 64 Checking Output Shaft Tolerances
Fig. 65 Checking Cluster Gear Journal Diameter
21 - 50 AX 15 MANUAL TRANSMISSIONJ

(8) Check fluid condition. Fluid should be dark to
light red in color and free of dirt or debris.
(9) If fluid is discolored or smells burned but trans-
mission operation was OK, check cooler flow, flush
cooler and lines and change fluid and filter. Then
road test again to confirm proper operation.
(10) If fluid is black or dark brown, burned/turned
to sludge, contains large quantities of metal or fric-
tion material particles, transmission will need over-
haul. Especially if problems were evident during
road test and preliminary diagnosis. Fluid cooler
should also be flow tested and flushed if necessary.
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. This aerates the fluid 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.
TRANSMISSION THROTTLE VALVE CABLE
ADJUSTMENT
Throttle cable adjustment is important to proper
operation. This adjustment positions the throttle
valve which controls shift speed, quality and part
throttle downshift sensitivity.
If cable adjustment setting is too short, early shifts
and slippage 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-Ve-
hicle 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. The Clutch and Band Applica-
tion chart (Fig. 3) provides a basis for analyzing road
test results.
ANALYZING THE ROAD TEST
Refer to the Clutch and Band Application chart
(Fig. 3) and note which elements are in use in the
various gear ranges.
The rear clutch is applied in all forward ranges (D,
2, 1). The overrunning clutch is applied in first gear
(D and 2 range only). The rear band is applied in 1
and R range only.
For example: If slippage occurs in first gear in D
and 2 range but not in 1 range, the overrunning
clutch is slipping. Similarly, if slippage occurs in any
two forward gears, the rear clutch is slipping.
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 select-
ing another gear which does not use one of these
units, the slipping clutch can be determined.
Although road test analysis will help determine
the slipping unit, the actual cause of a malfunction
may not be determined until hydraulic and air pres-
sure tests are performed. Practically any condition
Fig. 3 Clutch And Band Application Chart
21 - 70 30RH/32RH TRANSMISSION DIAGNOSISJ

(5) Line pressure should be 54-60 psi (372-414
kPa) with throttle lever forward and gradually in-
crease to 90-96 psi (620-662 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.
Both test gauges are required for this test.
(1) Connect one test gauge to line pressure port
and other gauge to front servo pressure port (Fig. 4).
Either gauge can be used at either port.
(2) Start and run engine at 1600 rpm.
(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 regu-
lation and the front clutch and rear servo cir-
cuits. Use 300 psi Pressure Test Gauge C-3293
for this test.
(1) Connect pressure test gauge to rear servo port
(Fig. 5).
(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 all way forward then all the
way 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
shift up or down. Use 100 psi Pressure Test
Gauge C-3292 for this test.
(1) Connect test gauge to governor pressure port
(Figs. 5 and 6).
(2) Move selector lever to D range.
(3) Apply service brakes. Start and run engine at
curb idle speed and note pressure. At idle and with
wheels stopped, pressure should be zero to 1-1/2 psi
maximum. If pressure exceeds this figure, governor
valve or weights are sticking open.(4) Slowly increase engine speed and observe
speedometer and pressure test gauge. Governor pres-
sure should increase in proportion to vehicle speed
(approximately 1 psi for every 1 mph shown on
speedometer).
(5) Governor pressure rise should be smooth and
drop back to 0 to 1-1/2 psi when throttle is closed
and wheels are stopped.
(6) Compare results of pressure tests with analysis
chart (Fig. 7).
CONVERTER STALL TEST
Stall testing involves determining maximum engine
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 overrun-
ning 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.
Fig. 7 Pressure Test Analysis Chart
21 - 72 30RH/32RH TRANSMISSION DIAGNOSISJ

30RH/32RH IN-VEHICLE SERVICE
INDEX
page page
Checking Fluid Level and Condition........... 96
Front Band Adjustment.................... 99
Gearshift Linkage Adjustment (YJ)............ 96
Governor and Park Gear Service............ 101
Oil Filter Replacement.................... 100
Park Interlock Cable Adjustment (XJ)......... 97
Park Lock Component Replacement......... 102
Park/Neutral Position Switch Service......... 103
Rear Band Adjustment.................... 99
Recommended Fluid...................... 96
Servicing Transmission Cooler Lines and Fittings. 106
Shift Cable Adjustment (XJ)................ 97
Speedometer Service.................... 103
Transmission Cooler Flow Testing........... 106
Transmission Cooler Reverse Flushing....... 105
Transmission Throttle Cable Adjustment (XJ/YJ) . 98
Valve Body Installation................... 101
Valve Body Removal..................... 100
Valve Body Service...................... 100
RECOMMENDED FLUID
The recommended and preferred fluid for 30RH/
32RH transmissions is Mopar ATF Plus, Type 7176.
Mopar Dexron II is acceptable but should only be
used when ATF Plus is not available.
Transmission fluid capacity is approximately 17
pints (7.9 liters). This is the approximate amount of
fluid required to fill the transmission and torque con-
verter after overhaul.
CHECKING FLUID LEVEL AND CONDITION
(1) Position vehicle on flat, level surface. This is
important in obtaining an accurate fluid level check.
(2) To avoid false readings, which could produce
under or over fill condition, do not check level until
fluid is at normal operating temperature.
(3) Shift transmission into Neutral.
(4) Apply parking brakes.
(5) Operate engine at curb idle speed.
WARNING: WHEN PERFORMING UNDERHOOD OP-
ERATIONS WITH THE ENGINE RUNNING, KEEP
YOUR HANDS WELL AWAY FROM HOT OR ROTAT-
ING ENGINE COMPONENTS. DO NOT WEAR
LOOSE ARTICLES OF CLOTHING WHICH COULD
BECOME ENTANGLED IN ENGINE COMPONENTS
OR ACCESSORIES.
(6) Shift transmission through all gear ranges and
back to Neutral (leave engine running).
(7) Clean exterior of dipstick cap and fill tube be-
fore removing transmission dipstick.
(8) Remove dipstick and inspect fluid level.
²Correct level is to FULL mark
²Acceptable level is between ADD and FULL marks
(9) Check fluid condition. Fluid should be dark to
light red in color and free of dirt or debris.
(10) If fluid is discolored or smells burned but
transmission operation was OK, check cooler flow,
flush cooler and lines and change fluid and filter.
Then road test again to confirm proper operation.(11) If fluid is black or dark brown, burned/turned
to sludge, contains large quantities of metal or fric-
tion material particles, transmission will need over-
haul. Especially if problems were evident during
road test and preliminary diagnosis. Fluid cooler
should also be flow tested and flushed if necessary.
GEARSHIFT LINKAGE ADJUSTMENT (YJ)
(1) Check linkage adjustment by starting engine in
Park and Neutral.
(2) Adjustment is OK if engine starts only in park
and Neutral. Adjustment is incorrect if engine starts
in one but not both positions.
(3) If engine starts in any position other than Park
or Neutral, or if engine will not start at all, park/
neutral position switch may be faulty.
(4) Shift transmission into Park.
(5) Raise vehicle.
(6) Check condition of shift rods, bellcrank, bell-
crank brackets and linkage bushings/grommets (Fig.
1). Tighten, repair, replace worn, damaged parts. Do
not attempt adjustment if linkage components are
worn or damaged.
(7) Loosen shift rod trunnion lock bolt or nut. Be
sure upper shift rod slides freely in trunnion (Fig. 1).
Also be sure shift rods and bellcrank rotate freely
and do not bind at any point.
(8) Verify that manual lever is in Park detent
(Fig. 1). Move lever all the way rearward to be sure
it is in Park.
(9) Check for positive engagement of park lock by
attempting to rotate propeller shaft. Shaft will not
turn when park pawl is engaged.
(10) Adjust shift rod trunnion to a obtain free pin
fit in bellcrank arm and tighten trunnion lock bolt or
nut. Prevent shift rod from turning while tightening
bolt or nut. Gearshift linkage lash must be elimi-
nated to obtain proper adjustment. Eliminate lash by
pulling downward on shift rod and pressing upward
on bellcrank.
21 - 96 30RH/32RH IN-VEHICLE SERVICEJ

The speedometer assembly used in XJ models is the
new unit type (one-piece) speed sensor (Fig. 16). How-
ever, YJ models may be equipped with either the new
unit style, or the older style that has a two-piece speed
sensor and a metal adapter (Fig. 16). Service procedures
for both styles are described in the following procedures.
SPEEDOMETER ASSEMBLY REMOVAL (WITH
UNIT STYLE SENSOR)
(1) Raise vehicle.
(2) Disconnect wires from vehicle speed sensor.
(3) Remove adapter clamp and screw (Fig. 16).
(4) Remove speed sensor and speedometer adapter
as assembly.
(5) Remove speed sensor retaining screw and re-
move sensor from adapter.
(6) Remove speedometer pinion from adapter.
(7) Inspect sensor and adapter O-rings (Fig. 16).
Remove and discard O-rings if worn or damaged.
(8) Inspect terminal pins in vehicle speed sensor.
Clean pins with Mopar electrical spray cleaner if
dirty or oxidized. Replace sensor if faulty, or pins are
loose, severely corroded, or damaged.
SPEEDOMETER INSTALLATION AND
INDEXING (UNIT STYLE)
(1) Thoroughly clean adapter flange and adapter
mounting surface in housing. Surfaces must be clean
for proper adapter alignment and speedometer oper-
ation.
(2) Install new O-rings on speed sensor and speed-
ometer adapter if necessary (Fig. 17).
(3) Lubricate sensor and adapter O-rings with
transmission fluid.(4) Install vehicle speed sensor in speedometer
adapter. Tighten sensor attaching screw to 2-3 Nzm
(15-27 in. lbs.) torque.
(5) Install speedometer pinion in adapter.
(6) Count number of teeth on speedometer pinion.
Do this before installing assembly in housing. Then
lubricate pinion teeth with transmission fluid.
(7) Note index numbers on adapter body (Fig. 17).
These numbers will correspond to number of teeth on
pinion.
(8) Install speedometer assembly in housing.
(9) Rotate adapter until requiredrange numbers
are at 6 o-clock position. Be sure range index num-
bers correspond to number of teeth on pinion gear.
Fig. 16 Speedometer Components (With Unit Style Sensor)
Fig. 17 Location Of Index Numbers On Speedometer
Adapter (Unit Style Sensor)
21 - 104 30RH/32RH IN-VEHICLE SERVICEJ

(10) Install speedometer adapter clamp and retain-
ing screw. Tighten clamp screw to 10-12 Nzm (90-110
in. lbs.) torque.
(11) Connect wires to vehicle speed sensor.
(12) Lower vehicle and top off transmission fluid
level if necessary.
SPEEDOMETER COMPONENT REMOVAL
(TWO-PIECE SENSOR)
(1) Raise vehicle.
(2) Disconnect speed sensor wires.
(3) Remove bolt attaching vehicle speed sensor to
sensor adapter. Then slide sensor out of adapter.
(4) Inspect speed sensor mounting area in sensor
adapter. If transmission fluid is found in this area,
oil seal in metal speedometer adapter is leaking and
will have to be replaced.
(5) Remove speedometer adapter clamp bolt and
remove clamp (Fig. 18).
(6) Remove speedometer adapter, sensor adapter
and speedometer pinion as assembly.
SPEEDOMETER COMPONENT INSTALLATION
AND INDEXING (TWO-PIECE SENSOR)
(1) Replace speedometer O-ring if cut, torn, or worn.
(2) If oil seal in metal speedometer adapter needs
replacement, remove old seal with pointed tool. Then
install new seal with Special Tool C-4004. Push seal
into place with tool until tool bottoms (Fig. 19).
(3) Clean speedometer adapter mounting surface of
transmission, or transfer case thoroughly.
(4) Lubricate adapter seals with transmission fluid.
(5) Count number of teeth on speedometer pinion.
Do this before installing pinion and adapter.
(6) Note range numbers on face of speedometer
adapter (Fig. 20). These numbers correspond to num-
ber of teeth on speedometer pinion.
(7) Install pinion in adapter and install assembled
pinion and adapter in transmission or transfer case.
(8) Rotate speedometer adapter until required
range numbers are at 6 o'clock position (Fig. 20).
Verify that range numbers correspond to num-
ber of teeth on pinion.
(9) Push speedometer adapter into place until seated.
(10) Install speedometer adapter clamp and bolt.
Tighten bolt to 11 Nzm (100 in. lbs.) torque.
(11) Install sensor adapter on speedometer adapter
(Fig. 18). Tighten sensor adapter coupling nut to 17
Nzm (150 in. lbs.) torque.
(12) Carefully align and insert vehicle speed sensor
into sensor adapter.
(13) Install bolt that attaches speed sensor to
adapter. Tighten bolt to 5-8 Nzm (48-72 in. lbs.)
(14) Connect wires to speed sensor.
(15) Lower vehicle.
(16) Check top off transmission fluid level if necessary.
TRANSMISSION COOLER REVERSE FLUSHING
The transmission main cooler is located in the ra-
diator lower tank. The cooler is not a serviceable
component. If the cooler is damaged in any way, the
radiator will have to be replaced.
On models with an auxiliary cooler, the cooler is
mounted in front of the radiator or air conditioningFig. 18 Speedometer Components (With Two-Piece
Sensor)
Fig. 19 Installing Speedometer Adapter Seal (With
Two-Piece Sensor And Metal Adapter)
Fig. 20 Indexing Speedometer Adapter (With Two-
Piece Sensor)
J30RH/32RH IN-VEHICLE SERVICE 21 - 105

(7) Remove front planetary rear thrust washer
from driving shell.
(8) Separate and remove driving shell, rear plane-
tary and rear annulus from output shaft (Fig. 78).
(9) Remove tabbed thrust washers from rear plan-
etary gear.(10) Remove snap ring that retains sun gear in
driving shell. Then remove sun gear, spacer and
thrust plates.
PLANETARY GEARTRAIN INSPECTION
Clean the planetary components in solvent and dry
them with compressed air.
Check sun gear and driving shell condition (Fig.
79). Replace the gear if damaged or if the bushings
are scored or worn. The bushings are not serviceable.
Replace the driving shell if worn, cracked or dam-
aged.
Replace planetary gear sets if gears, pinion pins, or
carrier are damaged in any way. Replace the annu-
lus gears and supports if either component is worn or
damaged.
Inspect the geartrain spacers, thrust plates, snap
rings, and thrust washers (Fig. 79). Replace any of
these parts that are worn, distorted or damaged. Do
not attempt to reuse these parts.
The planetary gear thrust washers are different
sizes. The large diameter washers go on the front
planetary and the smaller washers go on the rear
planetary. All the washers have four locating tabs on
them. These tabs fit in the holes or slots provided in
each planetary gear.
Inspect the output shaft carefully. Pay particular
attention to the machined bushing/bearing surfaces
on the shaft and the governor valve shaft bore at the
shaft rear.
Replace the output shaft if the machined surfaces
are scored, pitted, or damaged in any way. Also re-
place the shaft if the splines are damaged, or exhib-
its cracks at any location (especially at the governor
valve shaft bore).
The annulus gears can be removed from their sup-
ports if necessary. Just remove the snap rings and
separate the two parts when replacement is neces-
sary. In addition, the annulus gear bushings can be
replaced if severely worn, or scored. However it is
not necessary to replace the bushings if they only ex-
hibit normal wear. Check bushing fit on the output
shaft to be sure.
ASSEMBLING PLANETARY GEARTRAIN
(1) Lubricate output shaft and planetary compo-
nents with transmission fluid. Use petroleum jelly to
lubricate and hold thrust washers and plates in posi-
tion.
(2) Assemble rear annulus gear and support if dis-
assembled. Be sure support snap ring is seated and
that shoulder-side of support faces rearward (Fig.
80).
(3) Install rear thrust washer on rear planetary
gear (Fig. 79). Use enough petroleum jelly to hold
washer in place. Also be sure all four washer tabs
are properly engaged in gear slots.
Fig. 76 Front Planetary Snap Ring Removal
Fig. 77 Front Planetary And Annulus Gear
Disassembly
Fig. 78 Removing Driving Shell, Rear Planetary And
Rear Annulus
21 - 132 30RH/32RH TRANSMISSION OVERHAULJ

The valve body solenoids are controlled by signals
from the transmission control module (TCM). Signal
sequence is determined by vehicle speed and throttle
position.
Fourth gear is an 0.75:1 ratio overdrive range.
First, second, third and reverse gear are conventional
ranges. Third gear ratio is 1:1. A separate planetary
gear set provides overdrive operation in fourth gear.
TRANSMISSION RANGES AND SHIFT LEVER
POSITIONS
The AW-4 transmission has six ranges and shift le-
ver positions. Park, Reverse and Neutral are conven-
tional and mechanically operated. The 1-2, 3 and D
ranges provide electronically controlled shifting.
The 1-2 position provides first and second gear
only. The 3 position provides first, second and third
gear.
The D range provides first through fourth gear.
Overdrive fourth gear range is available only when
the shift lever is in D position (Fig. 2).
TRANSMISSION IDENTIFICATION
The transmission I.D. plate is attached to the case
(Fig. 3). The plate contains the transmission serial
and model numbers. Refer to the information on this
plate when ordering service parts.
COMPONENTS AND OPERATION
ELECTRONIC CONTROLS
The AW-4 is electronically controlled in the 1, 2, 3
and D ranges. Controls consist of the transmission
control module (TCM), valve body solenoids and var-ious sensors. The sensors monitor vehicle speed,
throttle opening, shift lever position and brake pedal
application.
TRANSMISSION CONTROL MODULE (TCM)
The module determines shift and converter clutch
engagement timing based on signals from the sen-
sors. The valve body solenoids are activated, or deac-
tivated accordingly.
The module has a self diagnostic program. Compo-
nent and circuitry malfunctions can be diagnosed
with the DRB II scan tool. Once a malfunction is
noted and stored in control module memory, it is re-
tained even after the problem has been corrected. To
cancel a stored malfunction, simply disconnect and
reconnect the9Trans.9fuse in the module harness.
TRANSMISSION VALVE BODY SOLENOIDS
The solenoids are mounted on the valve body and
operated by the transmission control module. The so-
lenoids control operation of the converter clutch and
shift valves in response to input signals from the
module.
SENSORS
The sensors include the throttle position sensor
(TPS), transmission output speed sensor, vehicle
speed sensor, park/neutral position switch and brake
switch.
The throttle position sensor is mounted on the
throttle body. It electronically determines throttle po-
sition and relays this information to the transmission
control module to determine shift points and con-
verter clutch engagement.
The transmission speed sensor consists of a rotor
and magnet on the transmission output shaft and a
switch in the extension housing or adapter. The sen-
sor switch is activated each time the rotor and mag-
Fig. 2 AW-4 Shift Lever Positions And Transmission
Ranges
Fig. 3 Transmission Identification
JAW-4 AUTOMATIC TRANSMISSION 21 - 157

Transmission Valve Body Solenoids
Three solenoids are used (Fig. 25). The No. 1 and 2
solenoids control shift valve operation by applying or
releasing line pressure. The signal to apply or release
pressure is provided by the transmission control
module.The No. 3 solenoid controls operation of the torque
converter clutch. The solenoid operates in response to
signals from the transmission control module.
When the No. 1 and 2 solenoids are activated, the
solenoid plunger is moved off its seat opening the
drain port to release line pressure. When either sole-
noid is deactivated, the plunger closes the drain port.
The No. 3 solenoid operates in reverse. When the
solenoid is deactivated, the solenoid plunger is moved
off its seat opening the drain port to release line
pressure. When the solenoid is activated, the plunger
closes the drain port.
Fig. 24 Accumulators
Fig. 25 Transmission Valve Body Solenoids
21 - 166 AW-4 AUTOMATIC TRANSMISSIONJ

BODY COMPONENTSÐREFINISHING
CONTENTS
page page
PAINT APPLICATION................... 201SERVICE INFORMATION................ 200
SERVICE INFORMATION
SAFETY PRECAUTIONS
Protective eye shields, masks, respirators, should
be used.
For maximum protection from paint solvent vapor,
use a fresh-air type, compressor-powered respirator.
PREPARATION
Do not allow any type of open flame or other source
of vapor ignition in the painting area. Paint vapor is
highly flammable when it is concentrated.
²Paint only in a well ventilated area.
²Use a good quality, high capacity respirator.
²Use protective goggles and clothing.
²Use rubber or latex gloves when mixing paint and
other, similar liquid products.
²When not in use, keep paint containers in a pro-
tective cabinet or locker.
²Keep the paint storage area well ventilated.
TECHNICAL TERMS
SINGLE COAT
A single-coat spray pattern is applied from left-to-
right. Then, the returning right-to-left spray pattern is
applied so that it overlaps the lower one-half of the ini-
tial spray pattern. This process is repeated until a com-
plete, single-coat coverage of a body panel is obtained.
DOUBLE COAT
A double-coat spray pattern is applied from left-to-
right. Then, the returning right-to-left spray pattern
is applied.
DRYING
Drying and hardening of paint film involves three
stages of evaporation.
The first stage is referred to as dust-free stage.
The second stage is referred to as tack-free stage.
The third and final stage is referred to as hard-dry0
stage.
DE-GREASE/DE-WAX
De-greasing/de-waxing involves cleaning a panel sur-
face with either 3M All purpose cleaner, or a similar
product. This removes the surface grease, or wax.
FEATHEREDGING
Tapering and blending the edges of repaired areas
is referred to as featheredging.
FERROUS AND NON-FERROUS METAL
Iron and steel are ferrous metals. Non-ferrous
metal includes aluminum, brass, copper, magnesium
and several types of alloy metal.
FLASH TIME
The time required for most of the solvent to evap-
orate from an applied primer/paint coat.
MIST COAT
A mist coat is frequently used as the final color
coat. Mist coats are over-thinned paint that is
sprayed wet.
SURFACE PRIMER COAT
A surface primer coat must be applied over re-
paired as well as bare metal substrate. The primer
provides a bond between the metal and the color
(base) coat. Various types of surface primers and
primer/sealants are available. Surface primers are
available in either sandable or non-sandable form.
Glazing or spot putty can be applied to primer cov-
ered surfaces. The putty is used to fill the small im-
perfections that a standard primer will not to cover.
REDUCERS/THINNERS
Enamel reducers and lacquer thinners are mix-
tures of volatile liquids and are used to reduce sur-
face primers and color-coat paints. Use only the type
of reducer/thinner that is specified by the paint man-
ufacturer.Do not intermix different types of re-
ducer/thinner.
TACK RAG
Tack rags are used to wipe dust from a body panel
surface prior to primer/paint application. Dust parti-
cles will adhere to the tacky surface of the rag when
it is moved over a panel surface.
23 - 200 BODY COMPONENTSÐXJ VEHICLESJ