DODGE RAM 2001 Service Repair Manual

ASSEMBLY
NOTE: The 42RE transmission uses four plates and
discs for the front clutch.
(1) Soak clutch discs in transmission fluid while
assembling other clutch parts.
(2) Install new seals in the clutch retainer lower
groove and on outer diameter of the retainer hub. Be
sure lip of each seal faces interior of clutch retainer.
(3) Lubricate lips of the retainer seals with liberal
quantity of MopartDoor Ease. Then lubricate
retainer hub, bore and piston with light coat of trans-
mission fluid.
(4) Install clutch piston in retainer (Fig. 89). Use
twisting motion to seat piston in bottom of retainer.
CAUTION: Never push the clutch piston straight in.
This will fold the seals over causing leakage and
clutch slip.
(5) Position spring in clutch piston (Fig. 90).
(6) Position spring retainer on top of piston spring.
Make sure retainer is properly installed (Fig. 85).
(7) Compress piston spring and retainer with Com-
pressor Tool C-3575-A (Fig. 86). Then install new
snap-ring to secure spring retainer and spring.
(8) Install clutch plates and discs (Fig. 85). Install
steel plate then disc until all plates and discs are
installed. The front clutch uses 4 clutch discs and
plates in a 42RE transmission.
(9) Install pressure plate and waved snap-ring
(Fig. 85).
Clearance should be 1.70 to 3.40 mm (0.067 to
0.134 in.). If clearance is incorrect, clutch discs,plates, pressure plates and snap-ring may have to be
changed.
FRONT SERVO
DESCRIPTION
The kickdown servo (Fig. 91) consists of a two-land
piston with an inner piston, a piston rod and guide,
and a return spring. The dual-land piston uses seal
rings on its outer diameters and an O-ring for the
inner piston.
Fig. 89 Front Clutch Piston Installation
1 - CLUTCH PISTON
2 - FRONT CLUTCH RETAINER
Fig. 90 Clutch Piston Spring Installation
1 - RETAINER
2 - CLUTCH SPRING
3 - PISTON
Fig. 91 Front Servo
1 - VENT
2 -PISTON ROD
3 - PISTON
4 - SPRING
5 - RELEASE PRESSURE
6 - APPLY PRESSURE
21 - 206 AUTOMATIC TRANSMISSION - 42REBR/BE
FRONT CLUTCH (Continued)

OPERATION
The application of the piston is accomplished by
applying pressure between the two lands of the pis-
ton. The pressure acts against the larger lower land
to push the piston downward, allowing the piston rod
to extend though its guide against the apply lever.
Release of the servo at the 2-3 upshift is accom-
plished by a combination of spring and line pressure,
acting on the bottom of the larger land of the piston.
The small piston is used to cushion the application of
the band by bleeding oil through a small orifice in
the larger piston. The release timing of the kickdown
servo is very important to obtain a smooth but firm
shift. The release has to be very quick, just as the
front clutch application is taking place. Otherwise,
engine runaway or a shift hesitation will occur. To
accomplish this, the band retains its holding capacity
until the front clutch is applied, giving a small
amount of overlap between them.
DISASSEMBLY
(1) Remove seal ring from rod guide (Fig. 92).
(2) Remove small snap-ring from servo piston rod.
Then remove piston rod, spring and washer from pis-
ton.
(3) Remove and discard servo component o-ring
and seal rings.
CLEANING
Clean the servo piston components (Fig. 93) with
solvent and dry them with compressed air.
INSPECTION
Inspect the servo components (Fig. 94). Replace the
springs if collapsed, distorted or broken. Replace the
guide, rod and piston if cracked, bent, or worn. Dis-
card the servo snap-ring if distorted or warped.
Check the servo piston bore for wear. If the bore is
severely scored, or damaged, it will be necessary to
replace the case.
Replace any servo component if doubt exists about
condition. Do not reuse suspect parts.
Fig. 92 Front Servo
1 - PISTON RINGS
2 - O-RING
3 - SNAP-RING
4 - SEAL RING
5 - PISTON ROD GUIDE
6 - SNAP-RING
7 - SERVO SPRING
8 - PISTON ROD
9 - SERVO PISTON
Fig. 93 Front Servo Piston
1 - PISTON RINGS
2 - O-RING
3 - SNAP-RING
4 - SEAL RING
5 - PISTON ROD GUIDE
6 - SNAP-RING
7 - SERVO SPRING
8 - PISTON ROD
9 - SERVO PISTON
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 207
FRONT SERVO (Continued)

ASSEMBLY
Clean and inspect front servo components.
(1) Lubricate new o-ring and seal rings with petro-
leum jelly and install them on piston, guide and rod.
(2)
Install rod in piston. Install spring and washer on
rod. Compress spring and install snap-ring (Fig. 95).
OIL PUMP
DESCRIPTION
The oil pump (Fig. 96) is located in the pump hous-
ing inside the bell housing of the transmission case.
The oil pump consists of an inner and outer gear
(Fig. 97), a housing, and a cover that also serves as
the reaction shaft support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate, the clearance between the gear teeth
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.Fig. 95 Front Servo
1 - PISTON RINGS
2 - O-RING
3 - SNAP-RING
4 - SEAL RING
5 - PISTON ROD GUIDE
6 - SNAP-RING
7 - SERVO SPRING
8 - PISTON ROD
9 - SERVO PISTON
Fig. 94 Front Servo Piston
1 - PISTON RINGS
2 - O-RING
3 - SNAP-RING
4 - SEAL RING
5 - PISTON ROD GUIDE
6 - SNAP-RING
7 - SERVO SPRING
8 - PISTON ROD
9 - SERVO PISTON
Fig. 96 Oil Pump and Reaction Shaft Support
1 - REACTION SHAFT SUPPORT
2 - PUMP
Fig. 97 Pump Gear Removal
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - OUTER GEAR
21 - 208 AUTOMATIC TRANSMISSION - 42REBR/BE
FRONT SERVO (Continued)

STANDARD PROCEDURE - OIL PUMP VOLUME
CHECK
Measuring the oil pump output volume will deter-
mine if sufficient oil flow to the transmission oil
cooler exists, and whether or not an internal trans-
mission failure is present.
Verify that the transmission fluid is at the proper
level. Refer to the Fluid Level Check procedure in
this section. If necessary, fill the transmission to the
proper level with MopartATF +4, type 9602, Auto-
matic Transmission Fluid.
(1) Disconnect theTo coolerline at the cooler
inlet and place a collecting container under the dis-
connected line.
CAUTION: With the fluid set at the proper level,
fluid collection should not exceed (1) quart or inter-
nal damage to the transmission may occur.
(2) Run the engineat curb idle speed, with the
shift selector in neutral.
(3) If one quart of transmission fluid is collected in
the container in 20 seconds or less, oil pump flow vol-
ume is within acceptable limits. If fluid flow is inter-
mittent, or it takes more than 20 seconds to collect
one quart of fluid, refer to the Hydraulic Pressure
tests in this section for further diagnosis.
(4) Re-connect theTo coolerline to the transmis-
sion cooler inlet.
(5) Refill the transmission to proper level.
DISASSEMBLY
(1) Remove seal ring from housing and reaction
shaft support (Fig. 98).
(2) Mark pump housing and support assembly for
alignment reference.
(3) Remove bolts attaching pump body to support
(Fig. 99).(4) Separate support from pump housing (Fig.
100).
Fig. 100 Separating Pump Housing From Reaction
Shaft Support
1 - REACTION SHAFT SUPPORT
2 - PUMP HOUSING
Fig. 98 Removing Pump Seal Ring
1 - PUMP HOUSING SEAL RING
Fig. 99 Pump Support Bolts
1 - REACTION SHAFT SUPPORT
2 - PUMP
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 209
OIL PUMP (Continued)

(5) Remove inner and outer gears from reaction
shaft support (Fig. 101).
(6) If pump seal was not removed during transmis-
sion disassembly, remove seal with punch and ham-
mer.
(7) Remove front clutch thrust washer from sup-
port hub (Fig. 102).
OIL PUMP BUSHING REPLACEMENT
(1) Remove pump bushing with Tool Handle
C-4171 and Bushing Remover SP-3551 from Tool Set
C-3887-J (Fig. 103).
(2) Install new pump bushing with Tool Handle
C-4171 and Bushing Installer SP-5117 (Fig. 103).
Bushing should be flush with pump housing bore.
(3) Stake new pump bushing in two places with
blunt punch (Fig. 104). Remove burrs from stake
points with knife blade afterward.
Fig. 101 Pump Gear Removal
1 - REACTION SHAFT SUPPORT
2 - INNER GEAR
3 - OUTER GEAR
Fig. 102 Support Hub Thrust Washer
1 - BUSHING
2 - REACTION SHAFT SUPPORT
3 - THRUST WASHER
4 - HUB
Fig. 103 Removing Oil Pump Bushing
1 - SPECIAL TOOL C-4171
2 - SPECIAL TOOL SP-3551
3 - BUSHING
4 - SPECIAL TOOL SP-5117
5 - BUSHING
6 - SPECIAL TOOL C-4171
7 - PUMP HOUSING
Fig. 104 Staking Oil Pump Bushing
1 - NARROW BLADE
2 - BLUNT PUNCH
3 - TWO STAKES
21 - 210 AUTOMATIC TRANSMISSION - 42REBR/BE
OIL PUMP (Continued)

REACTION SHAFT SUPPORT BUSHING REMOVAL
(1) Assemble Bushing Remover Tools SP-1191,
3633 and 5324 (Fig. 105). Do not clamp any part of
reaction shaft or support in vise.
(2) Hold Cup Tool SP-3633 firmly against reaction
shaft and thread remover SP-5324 into bushing as
far as possible by hand. Then thread remover tool 3-4
additional turns into bushing with a wrench.
(3) Turn remover tool hex nut down against
remover cup to pull bushing from shaft. Clean all
chips from shaft after bushing removal.
(4) Lightly grip old bushing in vise or with pliers
and back remover tool out of bushing.
(5) Assemble Bushing Installer Tools C-4171 and
SP-5325 (Fig. 105).
(6) Slide new bushing onto Installer Tool SP-5325.
(7) Position reaction shaft support upright on a
clean smooth surface.
(8) Align bushing in bore. Then tap bushing into
place until Bushing Installer SP-5325 bottoms.
(9) Clean reaction shaft support thoroughly after
installing bushing.
CLEANING
Clean pump and support components with solvent
and dry them with compressed air.
INSPECTION
Check condition of the seal rings and thrust
washer on the reaction shaft support. The seal rings
do not need to be replaced unless cracked, broken, or
severely worn.
Inspect the pump and support components. Replace
the pump or support if the seal ring grooves or
machined surfaces are worn, scored, pitted, or dam-
aged. Replace the pump gears if pitted, worn
chipped, or damaged.
Inspect the pump bushing. Then check the reaction
shaft support bushing. Replace either bushing only if
heavily worn, scored or damaged. It is not necessary
to replace the bushings unless they are actually dam-
aged.
Clearance between outer gear and reaction shaft
housing should be 0.010 to 0.063 mm (0.0004 to
0.0025 in.). Clearance between inner gear and reac-tion shaft housing should be 0.010 to 0.063 mm
(0.0004 to 0.0025 in.). Both clearances can be mea-
sured at the same time by installing the gears in the
pump body and measure pump component clearances
as follows:
(1) Position an appropriate piece of PlastigageŸ
across both gears.
(2) Align the plastigage to a flat area on the reac-
tion shaft housing.
(3) Install the reaction shaft to the pump housing.
(4) Separate the reaction shaft housing from the
pump housing and measure the PlastigageŸ follow-
ing the instructions supplied with it.
Clearance between inner gear tooth and outer gear
should be 0.08 to 0.19 mm (0.0035 to 0.0075 in.).
Measure clearance with an appropriate feeler gauge.
Clearance between outer gear and pump housing
should be 0.10 to 0.19 mm (0.004 to 0.0075 in.). Mea-
sure clearance with an appropriate feeler gauge.
Fig. 105 Replacing Reaction Shaft Support Bushing
1 - SPECIAL TOOL SP-1191
2 - SPECIAL TOOL SP-3633
3 - SPECIAL TOOL C-4171
4 - SPECIAL TOOL SP-5325
5 - REACTION SHAFT
6 - SPECIAL TOOL SP-5324
7 - BUSHING
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 211
OIL PUMP (Continued)

ASSEMBLY
(1) Lubricate gear bore in pump housing with
transmission fluid.
(2) Lubricate pump gears with transmission fluid.
(3) Support pump housing on wood blocks (Fig.
106).
(4) Install outer gear in pump housing (Fig. 106).
Gear can be installed either way (it is not a one-way
fit).
(5) Install pump inner gear (Fig. 107).
CAUTION: The pump inner gear is a one way fit.
The bore on one side of the gear inside diameter
(I.D.) is chamfered. Be sure the chamfered side
faces forward (to front of pump).(6) Install new thrust washer on hub of reaction
shaft support. Lubricate washer with transmission
fluid or petroleum jelly.
(7) If reaction shaft seal rings are being replaced,
install new seal rings on support hub (Fig. 108).
Lubricate seal rings with transmission fluid or petro-
leum jelly after installation. Squeeze each ring until
ring ends are securely hooked together.
CAUTION: The reaction shaft support seal rings will
break if overspread, or twisted. If new rings are
being installed, spread them only enough for instal-
lation. Also be very sure the ring ends are securely
hooked together after installation. Otherwise, the
rings will either prevent pump installation, or break
during installation.
(8) Install reaction shaft support on pump housing
(Fig. 109).
(9) Align reaction support on pump housing. Use
alignment marks made at disassembly. Or, rotate
support until bolt holes in support and pump housing
are all aligned (holes are offset for one-way fit).
Fig. 106 Supporting Pump And Installing Outer Gear
1 - OUTER GEAR
2 - PUMP HOUSING
3 - WOOD BLOCKS
Fig. 107 Pump Inner Gear Installation
1 - OUTER GEAR
2 - INNER GEAR
Fig. 108 Hub Seal Ring Position
1 - SEAL RINGS
2 - SUPPORT HUB
Fig. 109 Assembling Reaction Shaft Support And
Pump Housing
1 - PUMP HOUSING
2 - REACTION SHAFT SUPPORT
21 - 212 AUTOMATIC TRANSMISSION - 42REBR/BE
OIL PUMP (Continued)

(10) Install all bolts that attach support to pump
housing. Then tighten bolts finger tight.
(11) Tighten support-to-pump bolts to required
torque as follows:
(a) Reverse pump assembly and install it in
transmission case. Position pump so bolts are fac-
ing out and are accessible.
(b) Secure pump assembly in case with 2 or 3
bolts, or with pilot studs.
(c) Tighten support-to-pump bolts to 20 N´m (15
ft. lbs.).
(d) Remove pump assembly from transmission
case.
(12) Install new oil seal in pump with Special Tool
C-4193 and Tool Handle C-4171 (Fig. 110). Be sure
seal lip faces inward.
(13) Install new seal ring around pump housing.
Be sure seal is properly seated in groove.
(14) Lubricate lip of pump oil seal and O-ring seal
with transmission fluid.
OUTPUT SHAFT FRONT
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle.
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft front
bearing to overdrive geartrain. (Fig. 111).
(4) Pull bearing from output shaft.
INSTALLATION
(1) Place replacement bearing in position on
geartrain with locating retainer groove toward the
rear.
(2) Push bearing onto shaft until the snap-ring
groove is visible.
(3) Install snap-ring to hold bearing onto output
shaft.(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
OUTPUT SHAFT REAR
BEARING
REMOVAL
(1) Remove overdrive unit from the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC/
OVERDRIVE - REMOVAL)
(2) Remove overdrive geartrain from housing.
(3) Remove snap-ring holding output shaft rear
bearing into overdrive housing (Fig. 112).
(4) Using a suitable driver inserted through the
rear end of housing, drive bearing from housing.
INSTALLATION
(1) Place replacement bearing in position in hous-
ing.
(2) Using a suitable driver, drive bearing into
housing until the snap-ring groove is visible.
(3) Install snap-ring to hold bearing into housing
(Fig. 112).
(4) Install overdrive geartrain into housing.
(5) Install overdrive unit in vehicle.
Fig. 110 Pump Oil Seal Installation
1 - PUMP BODY
2 - PUMP SEAL
3 - SPECIAL TOOL C-4193
Fig. 111 Output Shaft Front Bearing
1 - OUTPUT SHAFT FRONT BEARING
2 - SNAP-RING
3 - OUTPUT SHAFT
4 - GROOVE TO REAR
5 - OVERDRIVE GEARTRAIN
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 213
OIL PUMP (Continued)

OVERDRIVE CLUTCH
DESCRIPTION
The overdrive clutch (Fig. 113) is composed of the
pressure plate, clutch plates, holding discs, overdrive
piston retainer, piston, piston spacer, and snap-rings.
The overdrive clutch is the forwardmost component
in the transmission overdrive unit and is considered
a holding component. The overdrive piston retainer,piston, and piston spacer are located on the rear of
the main transmission case.
NOTE: The number of discs and plates may vary
with each engine and vehicle combination.
OPERATION
To apply the clutch, pressure is applied between
the piston retainer and piston. The fluid pressure is
provided by the oil pump, transferred through the
control valves and passageways, and enters the
clutch through passages at the lower rear portion of
the valve body area. With pressure applied between
the piston retainer and piston, the piston moves
away from the piston retainer and compresses the
clutch pack. This action applies the clutch pack,
allowing torque to flow through the intermediate
shaft into the overdrive planetary gear set. The over-
drive clutch discs are attached to the overdrive clutch
hub while the overdrive clutch plates, reaction plate,
and pressure plate are lugged to the overdrive hous-
ing. This allows the intermediate shaft to transfer
the engine torque to the planetary gear and overrun-
ning clutch. This drives the planetary gear inside the
annulus, which is attached to the overdrive clutch
drum and output shaft, creating the desired gear
ratio. The waved snap-ring is used to cushion the
application of the clutch pack.
Fig. 113 Overdrive Clutch
1 - REACTION PLATE 2 - PRESSURE PLATE
Fig. 112 Output Shaft Rear Bearing
1 - OUTPUT SHAFT REAR BEARING
2 - OVERDRIVE HOUSING
3 - SNAP-RING
21 - 214 AUTOMATIC TRANSMISSION - 42REBR/BE
OUTPUT SHAFT REAR BEARING (Continued)

OVERDRIVE OFF SWITCH
DESCRIPTION
The overdrive OFF (control) switch is located in
the shift lever arm (Fig. 114). The switch is a
momentary contact device that signals the PCM to
toggle current status of the overdrive function.
OPERATION
At key-on, overdrive operation is allowed. Pressing
the switch once causes the overdrive OFF mode to be
entered and the overdrive OFF switch lamp to be
illuminated. Pressing the switch a second time
causes normal overdrive operation to be restored and
the overdrive lamp to be turned off. The overdrive
OFF mode defaults to ON after the ignition switch is
cycled OFF and ON. The normal position for the con-
trol switch is the ON position. The switch must be in
this position to energize the solenoid and allow a 3-4
upshift. The control switch indicator light illuminates
only when the overdrive switch is turned to the OFF
position, or when illuminated by the transmission
control module.
DIAGNOSIS AND TESTING - OVERDRIVE
ELECTRICAL CONTROLS
The overdrive off switch, valve body solenoid, case
connectors and related wiring can all be tested with
a 12 volt test lamp or a volt/ohmmeter. Check conti-
nuity of each component when diagnosis indicates
this is necessary.
Switch and solenoid continuity should be checked
whenever the transmission fails to shift into fourth
gear range.
REMOVAL
(1) Using a plastic trim tool, remove the overdrive
off switch retainer from the shift lever (Fig. 115).(2) Pull the switch outwards to release it from the
connector in the lever (Fig. 116)
INSTALLATION
NOTE: There is enough slack in the wire to pull out
the connector from the lever.
(1) Pull the connector out of the lever just enough
to grasp it.
CAUTION: Be careful not to bend the pins on the
overdrive off switch. Use care when installing the
switch, as it is not indexed, and can be accidentally
installed incorrectly.
Fig. 114 Overdrive Off Switch
Fig. 115 Overdrive Off Switch Retainer
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH RETAINER
3 - PLASTIC TRIM TOOL
Fig. 116 Remove the Overdrive Off Switch
1 - GEAR SHIFT LEVER
2 - OVERDRIVE OFF SWITCH
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 215