engine oil DODGE RAM 2001 Service Repair Manual

(9) Slide the steering pump from the bracket. Use
care not to damage the internal oil seal in the vac-
uum pump (Fig. 9).
(10) Remove the two pump body spacers.
INSTALLATION - GASOLINE ENGINE
(1) Install the front pump bracket and tighten
bolts to 47 N´m (35 ft. lbs.). On 8.0L engine install
rear pump bracket and tighten nut to 47 N´m (35 ft.
lbs.), tighten bolts to 24 N´m (18 ft. lbs.).
(2) Install the pump pulley with Installer
C-4063±B, (Refer to 19 - STEERING/PUMP/PULLEY
- INSTALLATION).
(3) Install steering pump assembly on the engine
block. Install the upper stud and bolt in bracket.
(4) Pivot the pump down past the coolant tube and
install the lower bolts in bracket.(5) Tighten the bolts and nut to 41 N´m (30 ft.
lbs.).
(6) Connect the hoses to the pump.
(7) Install the serpentine drive belt, (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION), (Refer to 7 - COOLING/ACCES-
SORY DRIVE/DRIVE BELTS - INSTALLATION).
(8) Fill the reservoir with power steering fluid,
(Refer to 19 - STEERING/PUMP - STANDARD PRO-
CEDURE).
INSTALLATION - DIESEL ENGINE
(1) Install the two pump body spacers.
(2) Rotate the drive gear until the steering pump
and vacuum pump drive dogs align. Install the steer-
ing pump onto the vacuum pump bracket. Use care
to avoid damaging the oil seal in the vacuum pump
during installation.The steering pump housing
and spacers must mate completely with the
vacuum pump bracket.
(3) Install the vacuum pump bracket to steering
pump nuts and tighten to 24 N´m (18 ft. lbs.).
(4) Position new gasket on vacuum pump assem-
bly. Use sealer if necessary to retain the gasket.
(5) Align and install the pump assembly on the
engine. Ensure the steering pump stud is inserted
into the block bracket. Tighten the pump- to-engine
block attaching bolts to 77 N´m (57 ft. lbs.).
(6) Install the steering pump to attaching bracket
nut and tighten to 24 N´m (18 ft. lbs.).
(7) Remove plug and install the oil pressure send-
ing unit and electrical connector.
(8) Install the oil feed line to the vacuum pump.
Tighten the oil line connection to 7 N´m (60 in. lbs./ 5
ft. lbs.).
(9) Install the fluid hoses to the power steering
pump. Tighten the pressure fitting at the pump to 31
N´m (23 ft. lbs.).
(10) Install and clamp the hose on the vacuum
pump.
(11) Install the serpentine belt, (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(12) Fill the reservoir with power steering fluid,
(Refer to 19 - STEERING/PUMP - STANDARD PRO-
CEDURE).
(13) Start the engine and check the operation of
the brakes.
Fig. 9 Steering Pump & Vacuum Pump
1 - PUMP SHAFT
2 - VACUUM FITTING
3 - VACUUM PUMP DRIVE
4 - OIL SEAL
5 - MOUNTING BRACKET
6 - DRIVE DOG
7 - PUMP SPACERS
BR/BEPUMP 19 - 35
PUMP (Continued)

The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
sleeve, the synchronizer begins to speed-up or slow
down the selected gear (depending on whether we are
up-shifting or down-shifting). The synchronizer does
this by having the synchronizer hub splined to the
mainshaft, or the countershaft in some cases, and
moving the blocker ring into contact with the gear's
friction cone. As the blocker ring and friction cone
come together, the gear speed is brought up or down
to the speed of the synchronizer. As the two speeds
match, the splines on the inside of the synchronizer
sleeve become aligned with the teeth on the blocker
ring and the friction cone and eventually will slide
over the teeth, locking the gear to the mainshaft, or
countershaft, through the synchronizer.
DIAGNOSIS AND TESTING - MANUAL
TRANSMISSION
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, adaptor or extension housing, or from the front/
rear seals. A suspected leak could also be the result
of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will probably be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening or use of a non-recommended sealer.
A leak at the front of the transmission will be from
either the front bearing retainer or retainer seal.
Lubricant may be seen dripping from the clutch
housing after extended operation. If the leak is
severe, it may also contaminate the clutch disc caus-
ing the disc to slip, grab and or chatter.
A correct lubricant level check can only be made
when the vehicle is level. Also allow the lubricant to
settle for a minute or so before checking. These rec-
ommendations will ensure an accurate check and
avoid an underfill or overfill condition. Always check
the lubricant level after any addition of fluid to avoid
an incorrect lubricant level condition.
HARD SHIFTING
Hard shifting is usually caused by a low lubricant
level, improper or contaminated lubricants. The con-sequence of using non-recommended lubricants is
noise, excessive wear, internal bind and hard shift-
ing. Substantial lubricant leaks can result in gear,
shift rail, synchro, and bearing damage. If a leak
goes undetected for an extended period, the first indi-
cations of component damage are usually hard shift-
ing and noise.
Component damage, incorrect clutch adjustment or
damaged clutch pressure plate or disc are additional
probable causes of increased shift effort. Incorrect
adjustment or a worn/damaged pressure plate or disc
can cause incorrect release. If clutch problem is
advanced, gear clash during shifts can result. Worn
or damaged synchro rings can cause gear clash when
shifting into any forward gear. In some new or
rebuilt transmissions, new synchro rings may tend to
stick slightly causing hard or noisy shifts. In most
cases this condition will decline as the rings wear-in.
TRANSMISSION NOISE
Most manual transmissions make some noise dur-
ing normal operation. Rotating gears generate a mild
whine that is audible, but generally only at extreme
speeds.
Severe highly audible transmission noise is gener-
ally the initial indicator of a lubricant problem.
Insufficient, improper or contaminated lubricant will
promote rapid wear of gears, synchros, shift rails,
forks and bearings. The overheating caused by a
lubricant problem, can also lead to gear breakage.
REMOVAL
(1) Disconnect battery negative cable.
(2) Shift transmission into Neutral.
(3) Remove shift boot bezel screws and slide boot
upward on shift lever extension.
(4) Remove shift lever extension from the shift
tower and lever assembly.
(5) Remove bolts attaching shift tower and lever
assembly to rear case. Then remove shift tower and
lever assembly.
(6) Raise vehicle on hoist.
(7) Remove crankshaft position sensor. Retain sen-
sor attaching bolts.
(8) Remove skid plate, if equipped.
(9) Drain transmission lubricant if transmission
will be disassembled for service.
(10) Mark propeller shaft/shafts and yoke/yokes for
installation reference and remove propeller shaft/
shafts.
(11) Disengage harness from clips on transmission
housing.
(12) Support engine with adjustable jack stand
and wood block.
(13) Drain transmission lubricant if transmission
will be disassembled for service.
BR/BEMANUAL - NV3500 21 - 3
MANUAL - NV3500 (Continued)

TWO WHEEL DRIVE
(1) Remove nuts attaching rear mount to cross-
member (Fig. 2). Then remove insulator from exten-
sion housing if necessary.
(2) Remove bolts and nuts attaching crossmember
to frame rails. Rotate crossmember diagonally and
remove crossmember.
(3) Disconnect exhaust as necessary.
(4) Remove slave cylinder attaching nuts and
remove cylinder from clutch housing.
(5) Remove starter motor.
(6) Support and secure transmission with safety
chains to a transmission jack.
(7) Remove nuts/bolts attaching transmission front
housing to engine.
(8) Remove transmission dust shield.
(9) Move transmission rearward until input shaft
is clear of clutch disc and cover. Then lower jack and
remove transmission from under vehicle.
FOUR WHEEL DRIVE
(1) Disconnect transfer case shift linkage at trans-
fer case range lever.
(2) Remove bolts attaching shift linkage bracket to
transfer case and move linkage and bracket aside.
(3) Support transfer case with transmission jack.
(4) Remove nuts attaching transfer case to trans-
mission adapter housing.(5) Remove transfer case with aid of helper.
(6) Support engine with a jack stand and a wood
block.
(7) Remove nuts and bolts attaching support
bracket and cushions to fixed crossmember.
(8) Remove nuts and bolts attaching removable
crossmember to frame rails.
(9) Remove crossmember.
(10) Disconnect exhaust as necessary.
(11) Remove slave cylinder attaching nuts and
remove cylinder from clutch housing. Move cylinder
aside for working clearance.
(12) Remove clutch housing dust cover.
(13) On some models, it may be necessary to
remove front axle struts and oil filter for access and
removal clearance. Remove these components if nec-
essary.
(14) Support transmission with transmission jack.
Secure transmission to jack with safety chains.
(15) Remove bolts attaching transmission clutch
housing to engine block.
(16) Move transmission rearward until transmis-
sion input shaft is clear of clutch disc and cover.
Then lower jack and remove transmission from under
vehicle.
Fig. 2 Transmission Rear Support Brackets
21 - 4 MANUAL - NV3500BR/BE
MANUAL - NV3500 (Continued)

SHIFT PATTERN
The shift pattern is in a modified H pattern (Fig.
2). Overdrive fifth and reverse gears are in line and
outboard of the first through fourth gear positions.
GEAR RATIOS
GEAR RATIO
FIRST 5.61:1
SECOND 3.04:1
THIRD 1.67:1
FOURTH 1.00:1
FIFTH 0.75:1
REVERSE 5.04:1
IDENTIFICATION
The transmission identification tag is attached to
the driver side PTO cover (Fig. 3).
The tag provides the transmission model number,
build date and part number. Be sure to reinstall the
I.D. tag if removed during service. The information
on the tag is essential to correct parts ordering.
OPERATION
The manual transmission receives power through
the clutch assembly from the engine. The clutch disc
is splined to the transmission input shaft and is
turned at engine speed at all times that the clutch is
engaged. The input shaft is connected to the trans-
mission countershaft through the mesh of fourth
speed gear on the input shaft and the fourth counter-
shaft gear. At this point, all the transmission gears
are spinning.
The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
sleeve, the synchronizer begins to speed-up or slowdown the selected gear (depending on whether we are
up-shifting or down-shifting). The synchronizer does
this by having the synchronizer hub splined to the
mainshaft, or the countershaft in some cases, and
moving the blocker ring into contact with the gear's
friction cone. As the blocker ring and friction cone
come together, the gear speed is brought up or down
to the speed of the synchronizer. As the two speeds
match, the splines on the inside of the synchronizer
sleeve become aligned with the teeth on the blocker
ring and the friction cone and eventually will slide
over the teeth, locking the gear to the mainshaft, or
countershaft, through the synchronizer.
DIAGNOSIS AND TESTING - MANUAL
TRANSMISSION
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, adaptor or extension housing, or from the front/
rear seals. A suspected leak could also be the result
of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will probably be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening or use of a non-recommended sealer.
Fig. 2 NV4500
Fig. 3 Identification Tag Location
1 - PTO COVER
2 - I.D. TAG
21 - 46 MANUAL - NV4500BR/BE
MANUAL - NV4500 (Continued)

SHIFT PATTERN
The shift pattern is in a modified H pattern (Fig.
2). Overdrive fifth and sixth gears are in line and
outboard of the first through fourth gear positions.
Reverse gear is to the right of fifth and sixth and for-
ward of the neutral gate.
GEAR RATIOS
GEAR RATIO
FIRST 5.63:1
SECOND 3.38:1
THIRD 2.04:1
FOURTH 1.39:1
FIFTH 1.00:1
SIXTH 0.73:1
REVERSE 5.63:1
IDENTIFICATION
The transmission has two identification tags
attached to the driver side upper clutch housing (Fig.
3).
One tag provides the transmission part number.
The second tag provides sequencing and build date
information. The information on the tags are essen-
tial to correct parts ordering.
OPERATION
The manual transmission receives power through
the clutch assembly from the engine. The clutch disc
is splined to the transmission input shaft and is
turned at engine speed at all times that the clutch is
engaged. The input shaft is connected to the trans-
mission countershaft through the mesh of fourth
speed gear on the input shaft and the fourth counter-
shaft gear. At this point, all the transmission gears
are spinning.The driver selects a particular gear by moving the
shift lever to the desired gear position. This move-
ment moves the internal transmission shift compo-
nents to begin the shift sequence. As the shift lever
moves the selected shift rail, the shift fork attached
to that rail begins to move. The fork is positioned in
a groove in the outer circumference of the synchro-
nizer sleeve. As the shift fork moves the synchronizer
sleeve, the synchronizer begins to speed-up or slow
down the selected gear (depending on whether we are
up-shifting or down-shifting). The synchronizer does
this by having the synchronizer hub splined to the
mainshaft, or the countershaft in some cases, and
moving the blocker ring into contact with the gear's
friction cone. As the blocker ring and friction cone
come together, the gear speed is brought up or down
to the speed of the synchronizer. As the two speeds
match, the splines on the inside of the synchronizer
sleeve become aligned with the teeth on the blocker
ring and the friction cone and eventually will slide
over the teeth, locking the gear to the mainshaft, or
countershaft, through the synchronizer.
DIAGNOSIS AND TESTING - MANUAL
TRANSMISSION
LOW LUBRICANT LEVEL
A low transmission lubricant level is generally the
result of a leak, inadequate lubricant fill or an incor-
rect lubricant level check.
Leaks can occur at the mating surfaces of the gear
case, adaptor or extension housing, or from the front/
rear seals. A suspected leak could also be the result
of an overfill condition.
Leaks at the rear of the extension or adapter hous-
ing will be from the housing oil seals. Leaks at com-
ponent mating surfaces will probably be the result of
inadequate sealer, gaps in the sealer, incorrect bolt
tightening or use of a non-recommended sealer.
Fig. 2 Shift Pattern
Fig. 3 Identification Tag Location
1 - IDENTIFICATION TAGS
BR/BEMANUAL - NV5600 21 - 93
MANUAL - NV5600 (Continued)

OVERRUNNING CLUTCH CAM/OVERDRIVE
PISTON RETAINER
DESCRIPTION..........................235
OPERATION............................235
DISASSEMBLY..........................235
CLEANING.............................236
INSPECTION...........................236
ASSEMBLY............................236
PARK/NEUTRAL POSITION SWITCH
DIAGNOSIS AND TESTING................237
PARK/NEUTRAL POSITION SWITCH.......237
REMOVAL.............................238
INSTALLATION..........................238
PISTONS
DESCRIPTION..........................238
OPERATION............................238
PLANETARY GEARTRAIN/OUTPUT SHAFT
DESCRIPTION..........................240
OPERATION............................240
DISASSEMBLY..........................240
INSPECTION...........................241
ASSEMBLY............................241
REAR CLUTCH
DESCRIPTION..........................246
OPERATION............................246
DISASSEMBLY..........................247
CLEANING.............................247
INSPECTION...........................248
ASSEMBLY............................248
REAR SERVO
DESCRIPTION..........................250
OPERATION............................250
DISASSEMBLY..........................251
CLEANING.............................251
ASSEMBLY............................251
SHIFT MECHANISM
DESCRIPTION..........................251OPERATION............................251
ADJUSTMENTS.........................252
SOLENOID
DESCRIPTION..........................252
OPERATION............................253
SPEED SENSOR
DESCRIPTION..........................253
OPERATION............................253
THROTTLE VALVE CABLE
DESCRIPTION..........................253
ADJUSTMENTS.........................254
TORQUE CONVERTER
DESCRIPTION..........................256
OPERATION............................260
REMOVAL.............................261
INSTALLATION..........................261
TORQUE CONVERTER DRAINBACK VALVE
DESCRIPTION..........................262
OPERATION............................262
STANDARD PROCEDURE.................262
TORQUE CONVERTER DRAINBACK VALVE . 262
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION..........................262
OPERATION............................262
VALVE BODY
DESCRIPTION..........................263
OPERATION............................267
REMOVAL.............................281
DISASSEMBLY..........................282
CLEANING.............................293
INSPECTION...........................293
ASSEMBLY............................294
INSTALLATION..........................303
ADJUSTMENTS.........................304
AUTOMATIC TRANSMISSION -
42RE
DESCRIPTION
The 42RE is a four speed fully automatic transmis-
sion (Fig. 1) with an electronic governor. The 42RE is
equipped with a lock-up clutch in the torque con-
verter. First through third gear ranges are provided
by the clutches, bands, overrunning clutch, and plan-
etary gear sets in the transmission. Fourth gear
range is provided by the overdrive unit that contains
an overdrive clutch, direct clutch, planetary gear set,
and overrunning clutch.
The transmission contains a front, rear, and direct
clutch which function as the input driving compo-
nents. It also contains the kickdown (front) and thelow/reverse (rear) bands which, along with the over-
running clutch and overdrive clutch, serve as the
holding components. The driving and holding compo-
nents combine to select the necessary planetary gear
components, in the front, rear, or overdrive planetary
gear set, transfer the engine power from the input
shaft through to the output shaft.
The valve body is mounted to the lower side of the
transmission and contains the valves to control pres-
sure regulation, fluid flow control, and clutch/band
application. The oil pump is mounted at the front of
the transmission and is driven by the torque con-
verter hub. The pump supplies the oil pressure nec-
essary for clutch/band actuation and transmission
lubrication.
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 135

IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan gas-
ket surface (Fig. 2). Refer to this information when
ordering replacement parts.
GEAR RATIOS The 42RE gear ratios are:
1st.................................2.74:1
2nd................................1.54:1
3rd.................................1.00:1
4th.................................0.69:1
Rev.................................2.21:1
OPERATION
The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position, throttle pressure, and gover-
nor pressure. The governor pressure is a variable
pressure input to the valve body and is one of the
signals that a shift is necessary. First through fourth
gear are obtained by selectively applying and releas-
ing the different clutches and bands. Engine power is
thereby routed to the various planetary gear assem-
blies which combine with the overrunning clutch
assemblies to generate the different gear ratios. The
torque converter clutch is hydraulically applied and
is released when fluid is vented from the hydraulic
circuit by the torque converter control (TCC) solenoid
on the valve body. The torque converter clutch is con-
trolled by the Powertrain Control Module (PCM). The
torque converter clutch engages in fourth gear, and
in third gear under various conditions, such as when
the O/D switch is OFF, when the vehicle is cruising
on a level surface after the vehicle has warmed up.
The torque converter clutch will disengage momen-
tarily when an increase in engine load is sensed by
the PCM, such as when the vehicle begins to go
uphill or the throttle pressure is increased. The
torque converter clutch feature increases fuel econ-
omy and reduces the transmission fluid temperature.
Since the overdrive clutch is applied in fourth gear
only and the direct clutch is applied in all ranges
except fourth gear, the transmission operation for
park, neutral, and first through third gear will be
described first. Once these powerflows are described,
the third to fourth shift sequence will be described.
1 - CONVERTER CLUTCH 15 - HOUSING
2 - TORQUE CONVERTER 16 - REAR BEARING
3 - OIL PUMP AND REACTION SHAFT SUPPORT ASSEMBLY 17 - OUTPUT SHAFT
4 - FRONT BAND 18 - SEAL
5 - FRONT CLUTCH 19 - OVERDRIVE OVERRUNNING CLUTCH
6 - DRIVING SHELL 20 - OVERDRIVE PLANETARY GEAR
7 - REAR BAND 21 - DIRECT CLUTCH SPRING
8 - TRANSMISSION OVERRUNNING CLUTCH 22 - OVERDRIVE CLUTCH PISTON
9 - OVERDRIVE UNIT 23 - VALVE BODY ASSEMBLY
10 - PISTON RETAINER 24 - FILTER
11 - OVERDRIVE CLUTCH 25 - FRONT PLANETARY GEAR
12 - DIRECT CLUTCH 26 - REAR CLUTCH
13 - INTERMEDIATE SHAFT 27 - TRANSMISSION
14 - FRONT BEARING 28 - REAR PLANETARY GEAR
Fig. 2 Transmission Part And Serial Number
Location
1 - PART NUMBER
2 - BUILD DATE
3 - SERIAL NUMBER
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 137
AUTOMATIC TRANSMISSION - 42RE (Continued)

PARK POWERFLOW
As the engine is running and the crankshaft is
rotating, the flexplate and torque converter, which
are also bolted to it, are all rotating in a clockwise
direction as viewed from the front of the engine. The
notched hub of the torque converter is connected to
the oil pump's internal gear, supplying the transmis-
sion with oil pressure. As the converter turns, it
turns the input shaft in a clockwise direction. As the
input shaft is rotating, the front clutch hub-rear
clutch retainer and all their associated parts are also
rotating, all being directly connected to the input
shaft. The power flow from the engine through the
front clutch hub and rear clutch retainer stops at the
rear clutch retainer. Therefore, no power flow to the
output shaft occurs because no clutches are applied.
The only mechanism in use at this time is the park-
ing sprag (Fig. 3), which locks the parking gear on
the output shaft to the transmission case.
NEUTRAL POWERFLOW
With the gear selector in the NEUTRAL position
(Fig. 4), the power flow of the transmission is essen-
tially the same as in the park position. The only
operational difference is that the parking sprag has
been disengaged, unlocking the output shaft from the
transmission case and allowing it to move freely.
Fig. 3 Park Powerflow
1 - PAWL ENGAGED FOR PARK
2 - PARK SPRAG
3 - OUTPUT SHAFT
Fig. 4 Neutral Powerflow
1 - PAWL DISENGAGED FOR NEUTRAL
2 - PARK SPRAG
3 - OUTPUT SHAFT
4 - CAM
5-PAWL
21 - 138 AUTOMATIC TRANSMISSION - 42REBR/BE
AUTOMATIC TRANSMISSION - 42RE (Continued)

FOURTH GEAR POWERFLOW
Fourth gear overdrive range is electronically con-
trolled and hydraulically activated. Various sensor
inputs are supplied to the powertrain control module
to operate the overdrive solenoid on the valve body.
The solenoid contains a check ball that opens and
closes a vent port in the 3-4 shift valve feed passage.
The overdrive solenoid (and check ball) are not ener-
gized in first, second, third, or reverse gear. The vent
port remains open, diverting line pressure from the
2-3 shift valve away from the 3-4 shift valve. The
overdrive control switch must be in the ON position
to transmit overdrive status to the PCM. A 3-4
upshift occurs only when the overdrive solenoid is
energized by the PCM. The PCM energizes the over-
drive solenoid during the 3-4 upshift. This causes the
solenoid check ball to close the vent port allowing
line pressure from the 2-3 shift valve to act directly
on the 3-4 upshift valve. Line pressure on the 3-4
shift valve overcomes valve spring pressure moving
the valve to the upshift position. This action exposes
the feed passages to the 3-4 timing valve, 3-4 quick
fill valve, 3-4 accumulator, and ultimately to the
overdrive piston. Line pressure through the timing
valve moves the overdrive piston into contact with
the overdrive clutch. The direct clutch is disengaged
before the overdrive clutch is engaged. The boost
valve provides increased fluid apply pressure to the
overdrive clutch during 3-4 upshifts, and when accel-
erating in fourth gear. The 3-4 accumulator cushions
overdrive clutch engagement to smooth 3-4 upshifts.
The accumulator is charged at the same time as
apply pressure acts against the overdrive piston.
DIAGNOSIS AND TESTING - AUTOMATIC
TRANSMISSION
Automatic transmission problems can be a result of
poor engine performance, incorrect fluid level, incor-
rect linkage or cable adjustment, band or hydraulic
control pressure adjustments, hydraulic system mal-
functions or electrical/mechanical component mal-
functions. Begin diagnosis by checking the easily
accessible items such as: fluid level and condition,
linkage adjustments and electrical connections. A
road test will determine if further diagnosis is neces-
sary.
DIAGNOSIS AND TESTING - PRELIMINARY
Two basic procedures are required. One procedure
for vehicles that are drivable and an alternate proce-
dure for disabled vehicles (will not back up or move
forward).
VEHICLE IS DRIVEABLE
(1) Check for transmission fault codes using DRBt
scan tool.(2) Check fluid level and condition.
(3) Adjust throttle and gearshift linkage if com-
plaint was based on delayed, erratic, or harsh shifts.
(4) Road test and note how transmission upshifts,
downshifts, and engages.
(5) Perform hydraulic pressure test if shift prob-
lems were noted during road test.
(6) Perform air-pressure test to check clutch-band
operation.
VEHICLE IS DISABLED
(1) Check fluid level and condition.
(2) Check for broken or disconnected gearshift or
throttle linkage.
(3) Check for cracked, leaking cooler lines, or loose
or missing pressure-port plugs.
(4) Raise and support vehicle on safety stands,
start engine, shift transmission into gear, and note
following:
(a) If propeller shaft turns but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shaft does not turn and transmis-
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis-
sion and check for damaged drive plate, converter,
oil pump, or input shaft.
(c) If propeller shaft does not turn and transmis-
sion is not noisy, perform hydraulic-pressure test to
determine if problem is hydraulic or mechanical.
DIAGNOSIS AND TESTING - ROAD TESTING
Before road testing, be sure the fluid level and con-
trol cable adjustments have been checked and
adjusted if necessary. Verify that diagnostic trouble
codes have been resolved.
Observe engine performance during the road test.
A poorly tuned engine will not allow accurate analy-
sis of transmission operation.
Operate the transmission in all gear ranges. Check
for shift variations and engine flare which indicates
slippage. Note if shifts are harsh, spongy, delayed,
early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means
clutch, band or overrunning clutch problems. If the
condition is advanced, an overhaul will 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 provides a basis for analyzing road test
results.
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 143
AUTOMATIC TRANSMISSION - 42RE (Continued)

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)