
plug threads and tighten plug to 17 N´m (150 in. lbs.)
torque.
(7) Adjust front band.
(8) Lubricate pump seal and converter hub with
transmission fluid or petroleum jelly and install con-
verter.
(9) Install transmission and converter housing
dust shield.
(10) Lower vehicle.
DIAGNOSIS AND TESTING - DIAGNOSIS
CHARTS
The diagnosis charts provide additional reference
when diagnosing a transmission fault. The chartsprovide general information on a variety of transmis-
sion, overdrive unit and converter clutch fault condi-
tions.
The hydraulic flow charts in the Schematics and
Diagrams section of this group, outline fluid flow and
hydraulic circuitry. Circuit operation is provided for
PARK, NEUTRAL, FIRST, SECOND, THIRD,
FOURTH, MANUAL FIRST, MANUAL SECOND,
and REVERSE gear ranges. Normal working pres-
sures are also supplied for each of the gear ranges.
DIAGNOSIS CHARTS
CONDITION POSSIBLE CAUSES CORRECTION
HARSH ENGAGEMENT
(FROM NEUTRAL TO
DRIVE OR REVERSE)1. Fluid Level Low. 1. Add Fluid
2. Throttle Linkage Mis-adjusted. 2. Adjust linkage - setting may be too long.
3. Mount and Driveline Bolts Loose. 3. Check engine mount, transmission
mount, propeller shaft, rear spring to body
bolts, rear control arms, crossmember and
axle bolt torque. Tighten loose bolts and
replace missing bolts.
4. U-Joint Worn/Broken. 4. Remove propeller shaft and replace
U-Joint.
5. Axle Backlash Incorrect. 5. Check per Service Manual. Correct as
needed.
6. Hydraulic Pressure Incorrect. 6. Check pressure. Remove, overhaul or
adjust valve body as needed.
7. Band Mis-adjusted. 7. Adjust rear band.
8. Valve Body Check Balls Missing. 8. Inspect valve body for proper check ball
installation.
9. Axle Pinion Flange Loose. 9. Replace nut and check pinion threads
before installing new nut. Replace pinion
gear if threads are damaged.
10. Clutch, band or planetary
component damaged.10. Remove, disassemble and repair
transmission as necessary.
11. Converter Clutch Faulty. 11. Replace converter and flush cooler and
line before installing new converter.
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 149
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
6. TPS Malfunction. 6. Replace sensor, check with DRBTscan
tool.
7. PCM Malfunction. 7. Check with DRBTscan tool and replace
if required.
8. Valve Body Malfunction. 8. Repair sticking 1-2, 2-3 shift valves,
governor plugs, 3-4 solenoid, 3-4 shift
valve, 3-4 timing valve.
STUCK IN LOW GEAR
(WILL NOT UPSHIFT)1. Throttle Linkage Mis-adjusted/
Stuck.1. Adjust linkage and repair linkage if worn
or damaged. Check for binding cable or
missing return spring.
2. Gearshift Linkage Mis-adjusted. 2. Adjust linkage and repair linkage if worn
or damaged.
3. Governor Component Electrical
Fault.3. Check operating pressures and test with
DRBTscan tool, repair faulty component.
4. Front Band Out of Adjustment. 4. Adjust Band.
5. Clutch or Servo Malfunction. 5. Air pressure check operation of clutches
and bands. Repair faulty component.
CREEPS IN NEUTRAL 1. Gearshift Linkage Mis-adjusted. 1. Adjust linkage.
2. Rear Clutch Dragging/Warped. 2. Disassemble and repair.
3. Valve Body Malfunction. 3. Perform hydraulic pressure test to
determine cause and repair as required.
BUZZING NOISE 1. Fluid Level Low 1. Add fluid and check for leaks.
2. Shift Cable Mis-assembled. 2. Route cable away from engine and bell
housing.
3. Valve Body Mis-assembled. 3. Remove, disassemble, inspect valve
body. Reassemble correctly if necessary.
Replace assembly if valves or springs are
damaged. Check for loose bolts or screws.
4. Pump Passages Leaking. 4. Check pump for porous casting, scores
on mating surfaces and excess rotor
clearance. Repair as required. Loose pump
bolts.
5. Cooling System Cooler Plugged. 5. Flow check cooler circuit. Repair as
needed.
6. Overrunning Clutch Damaged. 6. Replace clutch.
SLIPS IN REVERSE ONLY 1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Gearshift Linkage Mis-adjusted. 2. Adjust linkage.
3. Rear Band Mis-adjusted. 3. Adjust band.
4. Rear Band Worn. 4. Replace as required.
5. Overdrive Direct Clutch Worn. 5. Disassemble overdrive. Repair as
needed.
6. Hydraulic Pressure Too Low. 6. Perform hydraulic pressure tests to
determine cause.
7. Rear Servo Leaking. 7. Air pressure check clutch-servo operation
and repair as required.
8. Band Linkage Binding. 8. Inspect and repair as required.
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 153
AUTOMATIC TRANSMISSION - 42RE (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
3-4 UPSHIFT OCCURS
IMMEDIATELY AFTER 2-3
SHIFT1. Overdrive Solenoid Connector or
Wiring Shorted.1. Test connector and wiring for loose
connections, shorts or ground and repair as
needed.
2. TPS Malfunction. 2. Test TPS and replace as necessary.
Check with DRBTscan tool.
3. PCM Malfunction. 3. Test PCM with DRBTscan tool and
replace controller if faulty.
4. Overdrive Solenoid Malfunction. 4. Replace solenoid.
5. Valve Body Malfunction. 5. Remove, disassemble, clean and inspect
valve body components. Make sure all
valves and plugs slide freely in bores.
Polish valves with crocus cloth if needed.
WHINE/NOISE RELATED
TO ENGINE SPEED1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Shift Cable Incorrect Routing. 2. Check shift cable for correct routing.
Should not touch engine or bell housing.
NO 3-4 UPSHIFT 1. O/D Switch In OFF Position. 1. Turn control switch to ON position.
2. Overdrive Circuit Fuse Blown. 2. Replace fuse. Determine why fuse failed
and repair as necessary (i.e., shorts or
grounds in circuit).
3. O/D Switch Wire Shorted/Open
Cut.3. Check wires/connections with 12V test
lamp and voltmeter. Repair damaged or
loose wire/connection as necessary.
4. Distance or Coolant Sensor
Malfunction.4. Check with DRBTscan tool and repair or
replace as necessary.
5. TPS Malfunction. 5. Check with DRBTscan tool and replace
if necessary.
6. Neutral Sense to PCM Wire
Shorted/Cut.6. Test switch/sensor as described in
service section and replace if necessary.
Engine no start.
7. PCM Malfunction. 7. Check with DRBTscan tool and replace
if necessary.
8. Overdrive Solenoid Shorted/Open. 8. Replace solenoid if shorted or open and
repair loose or damaged wires (DRBTscan
tool).
9. Solenoid Feed Orifice in Valve
Body Blocked.9. Remove, disassemble, and clean valve
body thoroughly. Check feed orifice.
10. Overdrive Clutch Failed. 10. Disassemble overdrive and repair as
needed.
11. Hydraulic Pressure Low. 11. Pressure test transmission to determine
cause.
12. Valve Body Valve Stuck. 12. Repair stuck 3-4 shift valve, 3-4 timing
valve.
13. O/D Piston Incorrect Spacer. 13. Remove unit, check end play and install
correct spacer.
14. Overdrive Piston Seal Failure. 14. Replace both seals.
15. O/D Check Valve/Orifice Failed. 15. Check for free movement and secure
assembly (in piston retainer). Check ball
bleed orifice.
21 - 156 AUTOMATIC TRANSMISSION - 42REBR/BE
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)

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)

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

PROCEDURE ONE
(1) Transmission fluid must be at normal operat-
ing temperature for accurate fluid level check. Drive
vehicle if necessary to bring fluid temperature up to
normal hot operating temperature of 82ÉC (180ÉF).
(2) Position vehicle on level surface.
(3) Start and run engine at curb idle speed.
(4) Apply parking brakes.
(5) Shift transmission momentarily into all gear
ranges. Then shift transmission back to NEUTRAL.
(6) Clean top of filler tube and dipstick to keep
dirt from entering tube.
(7) Remove dipstick (Fig. 80) and check fluid level
as follows:
(a) Correct acceptable level is in crosshatch area.
(b) Correct maximum level is to MAX arrow
mark.
(c) Incorrect level is at or below MIN line.
(d) If fluid is low, add only enough MopartAT F
+4, type 9602, to restore correct level. Do not over-
fill.
PROCEDURE TWO
(1) Start engine and apply parking brake.
(2) Shift the transmission into DRIVE for approxi-
mately 2 seconds.
(3) Shift the transmission into REVERSE for
approximately 2 seconds.
(4) Shift the transmission into PARK.(5) Hook up DRBtscan tool and select engine.
(6) Select sensors.
(7) Read the transmission temperature value.
(8) Compare the fluid temperature value with the
figure. (Fig. 81)
(9) Adjust transmission fluid level shown on the
dipstick according to the figure.
NOTE: After adding any fluid to the transmission,
wait a minimum of 2 minutes for the oil to fully
drain from the fill tube into the transmission before
rechecking the fluid level.
(10) Check transmission for leaks.
Fig. 80 Dipstick Fluid Level Marks - Typical
1 - DIPSTICK
2 - MAXIMUM CORRECT FLUID LEVEL
3 - ACCEPTABLE FLUID LEVEL
Fig. 81 42/44RE Fluid Fill Graph
21 - 200 AUTOMATIC TRANSMISSION - 42REBR/BE
FLUID AND FILTER (Continued)

STANDARD PROCEDURE - FLUID AND FILTER
REPLACEMENT
For proper service intervals (Refer to LUBRICA-
TION & MAINTENANCE/MAINTENANCE SCHED-
ULES - DESCRIPTION). The service fluid fill after a
filter change is approximately 3.8 liters (4.0 quarts).
(1) Hoist and support vehicle on safety stands.
(2) Place a large diameter shallow drain pan
beneath the transmission pan.
(3) Remove bolts holding front and sides of pan to
transmission (Fig. 82).
(4) Loosen bolts holding rear of pan to transmis-
sion.
(5) Slowly separate front of pan away from trans-
mission allowing the fluid to drain into drain pan.
(6) Hold up pan and remove remaining bolt hold-
ing pan to transmission.
(7) While holding pan level, lower pan away from
transmission.
(8) Pour remaining fluid in pan into drain pan.
(9) Remove screws holding filter to valve body
(Fig. 83).
(10) Separate filter from valve body and pour fluid
in filter into drain pan.
(11) Dispose of used trans fluid and filter properly.
STANDARD PROCEDURE - TRANSMISSION
FILL
To avoid overfilling transmission after a fluid
change or overhaul, perform the following procedure:
(1) Remove dipstick and insert clean funnel in
transmission fill tube.
(2) Add following initial quantity of MopartAT F
+4, type 9602, to transmission:(a) If only fluid and filter were changed, add3
pints (1-1/2 quarts)of ATF +4 to transmission.
(b) If transmission was completely overhauled,
torque converter was replaced or drained, and
cooler was flushed, add12 pints (6 quarts)of ATF
+4 to transmission.
(3) Apply parking brakes.
(4) Start and run engine at normal curb idle
speed.
(5) Apply service brakes, shift transmission
through all gear ranges then back to NEUTRAL, set
parking brake, and leave engine running at curb idle
speed.
(6) Remove funnel, insert dipstick and check fluid
level. If level is low,add fluid to bring level to
MIN mark on dipstick.Check to see if the oil level
is equal on both sides of the dipstick. If one side is
noticably higher than the other, the dipstick has
picked up some oil from the dipstick tube. Allow the
oil to drain down the dipstick tube and re-check.
(7) Drive vehicle until transmission fluid is at nor-
mal operating temperature.
(8) With the engine running at curb idle speed, the
gear selector in NEUTRAL, and the parking brake
applied, check the transmission fluid level.
CAUTION: Do not overfill transmission, fluid foam-
ing and shifting problems can result.
(9) Add fluid to bring level up to MAX arrow
mark.
When fluid level is correct, shut engine off, release
park brake, remove funnel, and install dipstick in fill
tube.
Fig. 82 Transmission Pan
1 - TRANSMISSION
2 - GASKET
3-PAN
Fig. 83 Transmission Filter
1 - TRANSMISSION
2 - FILTER
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 201
FLUID AND FILTER (Continued)