
CONDITION POSSIBLE CAUSES CORRECTION
11. Pump Seal Leaks/Worn/
Damaged.11. Replace seal.
12. Torque Converter Weld
Leak/Cracked Hub.12. Replace converter.
13. Case Porosity Leaks. 13. Replace case.
NOISY OPERATION IN
FOURTH GEAR ONLY1. Overdrive Clutch Discs, Plates or
Snap Rings Damaged.1. Remove unit and rebuild clutch pack.
2. Overdrive Piston or Planetary
Thrust Bearing Damaged.2. Remove and disassemble unit. Replace
either thrust bearing if damaged.
3. Output Shaft Bearings Scored/
Damaged.3. Remove and disassemble unit. Replace
either bearing if damaged.
4. Planetary Gears Worn/Chipped. 4. Remove and overhaul overdrive unit.
5. Overdrive Unit Overrunning Clutch
Rollers Worn/Scored.5. Remove and overhaul overdrive unit.
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppliers.
REMOVAL
The overdrive unit can be removed and serviced
separately. It is not necessary to remove the entire
transmission assembly to perform overdrive unit
repairs.
(1) Disconnect battery negative cable.
(2) Disconnect and lower or remove necessary
exhaust components.
(3) Remove engine-to-transmission struts, if
equipped (Fig. 13).
(4) Disconnect fluid cooler lines at transmission.
(5) Remove starter motor. (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
(6) Disconnect and remove the crankshaft position
sensor. (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION/CRANKSHAFT POSITION SENSOR -
REMOVAL) Retain the sensor attaching bolts.
(7) Remove torque converter access cover.
(8)
If transmission is being removed for overhaul,
remove transmission oil pan, drain fluid and reinstall
pan.
(9) Remove fill tube bracket bolts and pull tube
out of transmission. Retain fill tube seal (Fig. 13). On
4 x 4 models, it will also be necessary to remove boltattaching transfer case vent tube to converter hous-
ing (Fig. 14).
(10) Rotate crankshaft in clockwise direction until
converter bolts are accessible. Then remove bolts one
at a time. Rotate crankshaft with socket wrench on
dampener bolt.
(11) Mark propeller shaft and axle yokes for
assembly alignment. Then disconnect and remove
propeller shaft. On4x4models, remove both propel-
ler shafts. (Refer to 3 - DIFFERENTIAL & DRIV-
Fig. 13 Transmission-To-Engine Strut Attachment
1 - ENGINE BLOCK
2 - STRUT (PASSENGER SIDE)
3 - ENGINE MOUNT
4 - STRUT (DRIVER SIDE)
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 159
AUTOMATIC TRANSMISSION - 42RE (Continued)

ELINE/PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL)
(12) Disconnect wires from park/neutral position
switch and transmission solenoid.
(13) Disconnect gearshift rod and torque shaft
assembly from transmission.
(14) Disconnect throttle valve cable from transmis-
sion bracket and throttle valve lever.
(15) On4x4models, disconnect shift rod from
transfer case shift lever.
(16)
Support rear of engine with safety stand or jack.
(17) Raise transmission slightly with service jack
to relieve load on crossmember and supports.
(18) Remove bolts securing rear support and cush-
ion to transmission and crossmember. Raise trans-
mission slightly, slide exhaust hanger arm from
bracket (Fig. 15) and remove rear support.
(19) Remove bolts attaching crossmember to frame
and remove crossmember.
(20) On4x4models, remove transfer case with
transmission jack or aid of helper.
(21) Remove all converter housing bolts.
(22) Carefully work transmission and torque con-
verter assembly rearward off engine block dowels.
(23) Lower transmission and remove assembly
from under the vehicle.
(24) To remove torque converter, remove C-clamp
from edge of bell housing and carefully slide torque
converter out of the transmission.
DISASSEMBLY
(1) Clean transmission exterior with steam gun or
with solvent. Wear eye protection during cleaning
operations.
(2) Place transmission in a vertical position.(3)
Measure input shaft end play as follows (Fig. 16).
(a) Attach Adapter 8266-6 to Handle 8266-8.
(b) Attach dial indicator C-3339 to Handle
8266-8.
(c)
Install the assembled tool onto the input shaft
of the transmission and tighten the retaining screw
on Adapter 8266-6 to secure it to the input shaft.
(d)Position the dial indicator plunger against a
flat spot on the oil pump and zero the dial indicator.
(e) Move the input shaft in and out. Record the
maximum travel for assembly reference.
Fig. 14 Fill Tube Attachment
1 - TRANSFER CASE VENT TUBE
2 - FILL TUBE (V8)
3 - TUBE SEAL
4 - FILL TUBE (V6)Fig. 15 Rear Support Cushion
1 - EXHAUST PIPE ARM AND BRACKET
2 - CROSSMEMBER
3 - REAR SUPPORT AND CUSHION
Fig. 16 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-6
3 - TOOL C-3339
21 - 160 AUTOMATIC TRANSMISSION - 42REBR/BE
AUTOMATIC TRANSMISSION - 42RE (Continued)

(a) Align and carefully insert park rod into pawl.
Rod will make click noise as it enters pawl. Move
rod slightly to check engagement.
(b) Align and seat valve body on case. Be sure
manual lever shaft and overdrive connector are
fully seated in case. Also be sure valve body wiring
is not pinched or kinked.
(c) Install and start all valve body attaching
bolts by hand. Then tighten bolts evenly, in a diag-
onal pattern to 12 N´m (105 in. lbs.) torque. Do not
overtighten valve body bolts. This could result in
distortion and cross leakage after installation.
CAUTION: It is possible for the park rod to displace
into a cavity just above the pawl sprag during
installation. Make sure the rod is actually engaged
in the pawl and has not displaced into the cavity.
(33) Install new filter on valve body. Tighten filter
screws to 4 N´m (35 in. lbs.).
(34) Adjust front and rear bands.
(35) Install seal on park/neutral position switch.
Then install and tighten switch to 34 N´m (25 ft.
lbs.).
(36) Install magnet in oil pan. Magnet goes on
small protrusion at corner of pan.
(37) Position new oil pan gasket on case and
install oil pan. Tighten pan bolts to 17 N´m (13 ft.
lbs.).
(38) Install new valve body manual shaft seal in
case (Fig. 55). Lubricate seal lip and manual shaft
with petroleum jelly. Start seal over shaft and into
case. Seat seal with 15/16 inch, deep well socket.
(39) Install throttle valve and shift selector levers
on valve body manual lever shaft.
Fig. 53 Checking Input Shaft End Play
1 - TOOL 8266-8
2 - TOOL 8266-6
3 - TOOL C-3339
Fig. 54 Accumulator Piston And Springs
1 - GOVERNOR PRESSURE SENSOR
2 - VALVE BODY
3 - PARK ROD
4 - ACCUMULATOR PISTON
5 - GOVERNOR PRESSURE SOLENOID
Fig. 55 Installing Manual Lever Shaft Seal
1 - 15/16©© SOCKET
2 - SEAL
21 - 172 AUTOMATIC TRANSMISSION - 42REBR/BE
AUTOMATIC TRANSMISSION - 42RE (Continued)

INSTALLATION
(1) Check torque converter hub and hub drive
notches for sharp edges burrs, scratches, or nicks.
Polish the hub and notches with 320/400 grit paper
and crocus cloth if necessary. The hub must be
smooth to avoid damaging pump seal at installation.
(2) Lubricate pocket in the rear oil pump seal lip
with transmission fluid.
(3) Lubricate converter pilot hub of the crankshaft
with a light coating of MopartHigh Temp Grease.
(4) Align and install converter in oil pump.
(5) Carefully insert converter in oil pump. Then
rotate converter back and forth until fully seated in
pump gears.
(6) Check converter seating with steel scale and
straightedge (Fig. 56). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) Temporarily secure converter with C-clamp.
(8) Position transmission on jack and secure it
with chains.
(9) Check condition of converter driveplate.
Replace the plate if cracked, distorted or damaged.
Also be sure transmission dowel pins are seated
in engine block and protrude far enough to
hold transmission in alignment.
(10) Raise transmission and align converter with
drive plate and converter housing with engine block.
(11) Move transmission forward. Then raise, lower
or tilt transmission to align converter housing with
engine block dowels.(12) Carefully work transmission forward and over
engine block dowels until converter hub is seated in
crankshaft.
(13) Install bolts attaching converter housing to
engine.
(14) Install rear support. Then lower transmission
onto crossmember and install bolts attaching trans-
mission mount to crossmember.
(15) Remove engine support fixture.
(16) Install crankshaft position sensor. (Refer to 14
- FUEL SYSTEM/FUEL INJECTION/CRANKSHAFT
POSITION SENSOR - INSTALLATION)
(17) Install new plastic retainer grommet on any
shift linkage rod or lever that was disconnected.
Grommets should not be reused. Use pry tool to
remove rod from grommet and cut away old grom-
met. Use pliers to snap new grommet into lever and
to snap rod into grommet at assembly.
(18) Connect gearshift and throttle cable to trans-
mission.
(19) Connect wires to park/neutral position switch,
transmission solenoid(s) and oxygen sensor. Be sure
transmission harnesses are properly routed.
CAUTION: It is essential that correct length bolts be
used to attach the converter to the driveplate. Bolts
that are too long will damage the clutch surface
inside the converter.
(20) Install torque converter-to-driveplate bolts.
On models with 10.75 in. converter, tighten bolts to
31 N´m (270 in. lbs.). On models with 12.2 in. con-
verter, tighten bolts to 47 N´m (35 ft. lbs.).
(21) Install converter housing access cover.
(22) Install starter motor and cooler line bracket.
(Refer to 8 - ELECTRICAL/STARTING/STARTER
MOTOR - INSTALLATION)
(23) Connect cooler lines to transmission.
(24) Install transmission fill tube. Install new seal
on tube before installation.
(25) Install exhaust components.
(26) Align and connect propeller shaft. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(27) Adjust gearshift linkage and throttle valve
cable if necessary.
(28) Lower vehicle.
(29) Fill transmission with MopartATF +4, type
9602, Automatic Transmission fluid.
Fig. 56 Checking Converter Seating - Typical
1 - SCALE
2 - STRAIGHTEDGE
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 173
AUTOMATIC TRANSMISSION - 42RE (Continued)

PRESSURE TEST
Overdrive clutch Fourth gear only Pressure should be 469-496 kPa (68-72 psi) with
closed throttle and increase to 620-896 kPa (90-130
psi) at 1/2 to 3/4 throttle.
Line pressure (at
accumulator)Closed throttle 372-414 kPa (54-60 psi).
Front servo Third gear only No more than 21 kPa (3 psi) lower than line pressure.
Rear servo 1 range No more than 21 kPa (3 psi) lower than line pressure.
R range 1103 kPa (160 psi) at idle, builds to 1862 kPa (270 psi)
at 1600 rpm.
Governor D range closed throttle Pressure should respond smoothly to changes in mph
and return to 0-7 kPa (0-1.5 psi) when stopped with
transmission in D, 1, 2. Pressure above 7 kPa (1.5 psi)
at stand still will prevent transmission from
downshifting.
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Fitting, cooler line at trans 18 13 -
Bolt, torque convertor 31 - 270
Bolt, clevis bracket to
crossmember47 35 -
Bolt, clevis bracket to rear support 68 50 -
Bolt, driveplate to crankshaft 75 55 -
Plug, front band reaction 17 13 -
Locknut, front band adj. 34 25 -
Switch, park/neutral 34 25 -
Bolt, fluid pan 17 13 -
Screws, fluid filter 4 - 35
Bolt, oil pump 20 15 -
Bolt, overrunning clutch cam 17 13 -
Bolt, O/D to trans. 34 25 -
Bolt, O/D piston retainer 17 13 -
Plug, pressure test port 14 10 -
Bolt, reaction shaft support 20 15 -
Locknut, rear band 41 30 -
Bolt, valve body to case 12 - 100
Sensor, trans speed 27 20 -
Screw, solenoid wiring connector 4 - 35
Screw, solenoid to transfer plate 4 - 35
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 187
AUTOMATIC TRANSMISSION - 42RE (Continued)

LOW/REVERSE (REAR) BAND
The rear band holds the rear planet carrier sta-
tionary by being mounted around and applied to the
low/reverse drum.
ADJUSTMENT - BANDS
FRONT BAND
The front (kickdown) band adjusting screw is
located on the left side of the transmission case
above the manual valve and throttle valve levers.
(1) Raise vehicle.
(2) Loosen band adjusting screw locknut (Fig. 64).
Then back locknut off 3-5 turns. Be sure adjusting
screw turns freely in case. Apply lubricant to screw
threads if necessary.
(3) Tighten band adjusting screw to 8 N´m (72 in.
lbs.) torque with Inch Pound Torque Wrench
C-3380-A, a 3-in. extension and appropriate TorxŸ
socket.
CAUTION: If Adapter C-3705 is needed to reach the
adjusting screw, tighten the screw to only 5 N´m
(47-50 in. lbs.) torque.
(4) Back off front band adjusting screw 3 turns.
(5) Hold adjuster screw in position and tighten
locknut to 41 N´m (30 ft. lbs.) torque.
(6) Lower vehicle.
REAR BAND
The transmission oil pan must be removed for
access to the rear band adjusting screw.
(1) Raise vehicle.
(2) Remove transmission oil pan and drain fluid.
(3) Loosen band adjusting screw locknut 5-6 turns
(Fig. 65). Be sure adjusting screw turns freely in
lever.
(4) Tighten adjusting screw to 8 N´m (72 in. lbs.)
torque.
(5) Back off adjusting screw 4 turns.
(6) Hold adjusting screw in place and tighten lock-
nut to 34 N´m (25 ft. lbs.) torque.
Fig. 63 Rear Band
1 - ADJUSTING SCREW
2 - LOCKNUT
3 - LEVER
4 - REAR BAND
5 - REACTION PIN
6 - O-RINGS
7 - PIVOT PINFig. 64 Front Band Adjustment Screw Location
1 - LOCK-NUT
2 - FRONT BAND ADJUSTER
Fig. 65 Rear Band Adjusting Screw Location
1 - ADJUSTING SCREW
2 - REAR BAND LEVER
3 - LOCKNUT
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 193
BANDS (Continued)

(7) Position new gasket on oil pan and install pan
on transmission. Tighten pan bolts to 17 N´m (13 ft.
lbs.) torque.
(8) Lower vehicle and refill transmission with
MopartATF +4, type 9602, fluid.
ELECTRONIC GOVERNOR
DESCRIPTION
Governor pressure is controlled electronically. Com-
ponents used for governor pressure control include:
²Governor body
²Valve body transfer plate
²Governor pressure solenoid valve
²Governor pressure sensor
²Fluid temperature thermistor
²Throttle position sensor (TPS)
²Transmission speed sensor
²Powertrain control module (PCM)
GOVERNOR PRESSURE SOLENOID VALVE
The solenoid valve is a duty-cycle solenoid which
regulates the governor pressure needed for upshifts
and downshifts. It is an electro-hydraulic device
located in the governor body on the valve body trans-
fer plate (Fig. 66).
GOVERNOR PRESSURE SENSOR
The governor pressure sensor measures output
pressure of the governor pressure solenoid valve (Fig.
67).
GOVERNOR BODY AND TRANSFER PLATE
The transfer plate is designed to supply transmis-
sion line pressure to the governor pressure solenoid
valve and to return governor pressure.
The governor pressure solenoid valve is mounted in
the governor body. The body is bolted to the lower
side of the transfer plate (Fig. 67).
GOVERNOR PRESSURE CURVES
There are four governor pressure curves pro-
grammed into the transmission control module. The
different curves allow the control module to adjust
governor pressure for varying conditions. One curve
is used for operation when fluid temperature is at, or
below, ±1ÉC (30ÉF). A second curve is used when fluid
temperature is at, or above, 10ÉC (50ÉF) during nor-
mal city or highway driving. A third curve is used
during wide-open throttle operation. The fourth curve
is used when driving with the transfer case in low
range.
OPERATION
Compensation is required for performance varia-
tions of two of the input devices. Though the slope of
the transfer functions is tightly controlled, offset may
vary due to various environmental factors or manu-
facturing tolerances.
The pressure transducer is affected by barometric
pressure as well as temperature. Calibration of the
zero pressure offset is required to compensate for
shifting output due to these factors.
Normal calibration will be performed when sump
temperature is above 50 degrees F, or in the absence
of sump temperature data, after the first 10 minutes
of vehicle operation. Calibration of the pressure
transducer offset occurs each time the output shaft
speed falls below 200 RPM. Calibration shall be
repeated each 3 seconds the output shaft speed is
below 200 RPM. A 0.5 second pulse of 95% duty cycle
is applied to the governor pressure solenoid valve
and the transducer output is read during this pulse.
Averaging of the transducer signal is necessary to
reject electrical noise.
Fig. 66 Governor Pressure Solenoid Valve
1 - SOLENOID FILTER
2 - GOVERNOR PRESSURE SOLENOID
Fig. 67 Governor Pressure Sensor
1 - GOVERNOR BODY
2 - GOVERNOR PRESSURE SENSOR/TRANSMISSION FLUID
TEMPERATURE THERMISTOR
21 - 194 AUTOMATIC TRANSMISSION - 42REBR/BE
BANDS (Continued)

FLUID AND FILTER
DIAGNOSIS AND TESTING - 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 and causing
the same conditions occurring with a low level. In
either case, air bubbles cause fluid overheating, oxi-
dation and varnish buildup which interferes with
valve and clutch operation. Foaming also causes fluid
expansion which can result in fluid overflow from the
transmission vent or fill tube. Fluid overflow can eas-
ily be mistaken for a leak if inspection is not careful.
DIAGNOSIS AND TESTING - CAUSES OF
BURNT FLUID
Burnt, discolored fluid is a result of overheating
which has two primary causes.
(1) A result of restricted fluid flow through the
main and/or auxiliary cooler. This condition is usu-
ally the result of a faulty or improperly installed
drainback valve, a damaged main cooler, or severe
restrictions in the coolers and lines caused by debris
or kinked lines.
(2) Heavy duty operation with a vehicle not prop-
erly equipped for this type of operation. Trailer tow-
ing or similar high load operation will overheat the
transmission fluid if the vehicle is improperly
equipped. Such vehicles should have an auxiliary
transmission fluid cooler, a heavy duty cooling sys-
tem, and the engine/axle ratio combination needed to
handle heavy loads.
DIAGNOSIS AND TESTING - FLUID
CONTAMINATION
Transmission fluid contamination is generally a
result of:
²adding incorrect fluid
²failure to clean dipstick and fill tube when
checking level
²engine coolant entering the fluid
²internal failure that generates debris
²
overheat that generates sludge (fluid breakdown)
²failure to reverse flush cooler and lines after repair
²failure to replace contaminated converter after
repair
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 for-
eign 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 withdrawing 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, an overhaul is necessary.
The transmission cooler and lines should be
reverse flushed whenever a malfunction generates
sludge and/or debris. The torque converter should
also be replaced at the same time.
Failure to flush the cooler and lines will result in
recontamination. Flushing applies to auxiliary coolers
as well. The torque converter should also be replaced
whenever a failure generates sludge and debris. This is
necessary because normal converter flushing procedures
will not remove all contaminants.
STANDARD PROCEDURE - FLUID LEVEL
CHECK
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transmssion has too much fluid, the
geartrain churns up foam and cause the same condi-
tions which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can inter-
fere with normal valve, clutch, and accumulator opera-
tion. Foaming can also result in fluid escaping from the
transmission vent where it may be mistaken for a leak.
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transmission recondition is
needed. Be sure to examine the fluid on the dipstick
closely. If there is any doubt about its condition,
drain out a sample for a double check.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
The transmission has a dipstick to check oil level.
It is located on the right side of the engine. Be sure
to wipe all dirt from dipstick handle before removing.
Fluid level is checked with the engine running at curb
idle speed, the transmission in NEUTRAL and the trans-
mission fluid at normal operating temperature.The
engine should be running at idle speed for at least
one minute, with the vehicle on level ground.
The transmission fluid level can be checked two
ways.
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 199