2001 DODGE RAM lock

GEAR CASE AND PARK LOCK
(1) Remove locating ring from gear case.
(2) Remove park pawl shaft retaining bolt and
remove shaft, pawl and spring.
(3) Remove reaction plug snap-ring and remove
reaction plug.
(4) Remove output shaft seal.
CLEANING
Clean the geartrain and case components with sol-
vent. Dry all parts except the bearings with com-
pressed air. Allow bearings to air dry.
Do not use shop towels for wiping parts dry unless
the towels are made from a lint-free material. A suf-
ficient quantity of lint (from shop towels, cloths, rags,
etc.) could plug the transmission filter and fluid pas-
sages.
Discard the old case gasket and seals. Do not
attempt to salvage these parts. They are not reus-
able. Replace any of the overdrive unit snap-rings if
distorted or damaged.
Minor nicks or scratches on components can be
smoothed with crocus cloth. However, do not attempt
to reduce severe scoring on any components with
abrasive materials. Replace severely scored compo-
nents; do not try to salvage them.
INSPECTION
Check condition of the park lock components and
the overdrive case.
Check the bushings in the overdrive case. Replace
the bushings if severely scored or worn. Also replace
the case seal if loose, distorted, or damaged.
Examine the overdrive and direct clutch discs and
plates. Replace the discs if the facing is worn,
severely scored, or burned and flaking off. Replace
the clutch plates if worn, heavily scored, or cracked.
Check the lugs on the clutch plates for wear. The
plates should slide freely in the drum. Replace the
plates or drum if binding occurs.
Check condition of the annulus gear, direct clutch
hub, clutch drum and clutch spring. Replace the gear,
hub and drum if worn or damaged. Replace the
spring if collapsed, distorted, or cracked.
Be sure the splines and lugs on the gear, drum and
hub are in good condition. The clutch plates and
discs should slide freely in these components.
Inspect the thrust bearings and spring plate.
Replace the plate if worn or scored. Replace the bear-
ings if rough, noisy, brinnelled, or worn.
Inspect the planetary gear assembly and the sun
gear and bushings. If either the sun gear or the
bushings are damaged, replace the gear and bush-
ings as an assembly. The gear and bushings are not
serviced separately.
The planetary carrier and pinions must be in good
condition. Also be sure the pinion pins are secure and
in good condition. Replace the carrier if worn or dam-
aged.
Inspect the overrunning clutch and race. The race
surface should be smooth and free of scores. Replace
the overrunning clutch assembly or the race if either
assembly is worn or damaged in any way.
Replace the shaft pilot bushing and inner bushing
if damaged. Replace either shaft bearing if rough or
noisy. Replace the bearing snap-rings if distorted or
cracked.
Check the machined surfaces on the output shaft.
These surfaces should clean and smooth. Very minor
nicks or scratches can be smoothed with crocus cloth.
Replace the shaft if worn, scored or damaged in any
way.
Inspect the output shaft bushings. The small bush-
ing is the intermediate shaft pilot bushing. The large
bushing is the overrunning clutch hub bushing.
Replace either bushing if scored, pitted, cracked, or
worn.
Fig. 146 Annulus Gear Removal
1 - OUTPUT SHAFT
2 - ANNULUS GEAR
21 - 224 AUTOMATIC TRANSMISSION - 42REBR/BE
OVERDRIVE UNIT (Continued)

(8) Install overrunning clutch on hub (Fig. 152).
Note that clutch only fits one-way. Shoulder on clutch
should seat in small recess at edge of hub.
(9) Install thrust bearing on overrunning clutch
hub. Use generous amount of petroleum jelly to hold
bearing in place for installation. Bearing fits one-way
only. Be sure bearing is seated squarely against hub.
Reinstall bearing if it does not seat squarely.
(10) Install overrunning clutch in output shaft
(Fig. 153). Insert snap-ring pliers in hub splines.
Expand pliers to grip hub. Then install assembly
with counterclockwise, twisting motion.
(11) Install planetary gear in annulus gear (Fig.
154). Be sure planetary pinions are fully seated in
annulus gear before proceeding.
(12) Coat planetary thrust bearing and bearing
contact surface of spring plate with generous amount
of petroleum jelly. This will help hold bearing in
place during installation.
Fig. 151 Rear Bearing And Snap-Ring Installation
1 - REAR BEARING
2 - SNAP-RING
Fig. 152 Assembling Overrunning Clutch And Hub
1 - CLUTCH HUB
2 - OVERRUNNING CLUTCH
Fig. 153 Overrunning Clutch Installation
1 - CLUTCH DRUM
2 - OVERRUNNING CLUTCH ASSEMBLY
3 - EXPANDING-TYPE SNAP-RING PLIERS
4 - CLUTCH DRUM
5 - ANNULUS GEAR
6 - OVERRUNNING CLUTCH ASSEMBLY SEATED IN OUTPUT
SHAFT
Fig. 154 Planetary Gear Installation
1 - PLANETARY GEAR
2 - ANNULUS GEAR
21 - 226 AUTOMATIC TRANSMISSION - 42REBR/BE
OVERDRIVE UNIT (Continued)

GEAR CASE
(1) Position park pawl and spring in case and
install park pawl shaft. Verify that end of spring
with 90É bend is hooked to pawl and straight end of
spring is seated against case.
(2) Install pawl shaft retaining bolt. Tighten bolt
to 27 N´m (20 ft. lbs.) torque.
(3) Install park lock reaction plug. Note that plug
has locating pin at rear (Fig. 165). Be sure pin is
seated in hole in case before installing snap-ring.
(4) Install reaction plug snap-ring (Fig. 166). Com-
press snap ring only enough for installation; do not
distort it.(5) Install new seal in gear case. On 4x4 gear case,
use Tool Handle C-4171 and Installer C-3860-A to
seat seal in case. On4x2gear case, use same Han-
dle C-4171 and Installer C-3995-A to seat seal in
case.
(6) Verify that tab ends of rear bearing locating
ring extend into access hole in gear case (Fig. 167).
(7) Support geartrain on Tool 6227-1 (Fig. 168). Be
sure tool is securely seated in clutch hub.
(8) Install overdrive gear case on geartrain (Fig.
168).
Fig. 164 Clutch Hub Retaining Ring Installation
1 - SPECIAL TOOL 6227-1
2 - CLUTCH HUB RETAINING RING
Fig. 165 Reaction Plug Locating Pin And Snap-Ring
1 - REACTION PLUG SNAP-RING (DO NOT OVERCOMPRESS
TO INSTALL)
2 - LOCATING PIN
3 - PARK LOCK REACTION PLUG
Fig. 166 Reaction Plug And Snap-Ring Installation
1 - REACTION PLUG SNAP-RING
2 - SNAP-RING PLIERS
Fig. 167 Correct Rear Bearing Locating Ring
Position
1 - CASE ACCESS HOLE
2 - TAB ENDS OF LOCATING RING
21 - 230 AUTOMATIC TRANSMISSION - 42REBR/BE
OVERDRIVE UNIT (Continued)

(9) Expand front bearing locating ring with snap-
ring pliers (Fig. 169). Then slide case downward until
locating ring locks in bearing groove and release
snap-ring.
(10) Install locating ring access cover and gasket
in overdrive unit case (Fig. 170).
OVERDRIVE CLUTCH
(1) Install overdrive clutch reaction ring first.
Reaction ring is flat with notched ends (Fig. 171).
(2) Install wave spring on top of reaction ring (Fig.
172). Reaction ring and wave ring both fit in same
ring groove. Use screwdriver to seat each ring
securely in groove. Also ensure that the ends of the
two rings are offset from each other.NOTE: The 42RE transmission has 3 overdrive
clutch discs and 2 plates.
(3) Assemble overdrive clutch pack (Fig. 173).
(4) Install overdrive clutch reaction plate first.
NOTE: The reaction plate is thinner than the pres-
sure plate in a 42RE transmission.
Fig. 168 Overdrive Gear Case Installation
1 - GEARTRAIN ASSEMBLY
2 - GEAR CASE
Fig. 169 Seating Locating Ring In Rear Bearing
1 - EXPAND BEARING LOCATING RING WITH SNAP-RING
PLIERS
2 - ACCESS HOLE
Fig. 170 Locating Ring Access Cover And Gasket
Installation
1 - TORX SCREWDRIVER (T25)
2 - ACCESS COVER SCREWS
Fig. 171 Overdrive Clutch Reaction Ring Installation
1 - REACTION RING
2 - CLUTCH HUB
Fig. 172 Overdrive Clutch Wave Spring Installation
1 - WAVE SPRING
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 231
OVERDRIVE UNIT (Continued)

(5) Install first clutch disc followed by first clutch
plate. Then install remaining clutch discs and plates
in same order.
(6) Install clutch pack pressure plate.
(7) Install clutch pack wire-type retaining ring
(Fig. 174).INTERMEDIATE SHAFT SPACER SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
mounting hole cut into it. Be sure unit is facing
upward for access to direct clutch hub. Also be sure
output shaft is not loaded and internal components
are moved rearward for accurate measurement.
(2) Determine correct thickness intermediate shaft
spacer as follows:
(a) Insert Special Tool 6312 through sun gear,
planetary gear and into pilot bushing in output
shaft. Be sure tool bottoms against planetary
shoulder.
(b) Position Gauge Tool 6311 across face of over-
drive case (Fig. 175). Then position Dial Caliper
C-4962 over gauge tool.
(c) Extend sliding scale of dial caliper downward
through gauge tool slot until scale contacts end of
Gauge Alignment Tool 6312. Lock scale in place.
Remove dial caliper tool and note distance mea-
sured (Fig. 175).
(d) Select proper thickness end play spacer from
spacer chart based on distance measured (Fig.
176).
(e) Remove Gauge Alignment Tool 6312.
OD THRUST PLATE SELECTION
(1) Place overdrive unit in vertical position. Mount
it on blocks, or in workbench with appropriate size
Fig. 173 42RE Overdrive Clutch Components
1 - REACTION PLATE 2 - PRESSURE PLATE
Fig. 174 Overdrive Clutch Pack Retaining Ring
Installation
1 - OVERDRIVE CLUTCH PACK RETAINING RING
21 - 232 AUTOMATIC TRANSMISSION - 42REBR/BE
OVERDRIVE UNIT (Continued)

(d) Push overdrive piston into position in
retainer.
(e) Verify that the locating lugs entered the lug
bores in the retainer.
(6) Install intermediate shaft spacer on intermedi-
ate shaft.
(7) Install overdrive piston thrust plate on over-
drive piston.
(8) Install overdrive piston thrust bearing on over-
drive piston.
(9) Install transmission speed sensor and O-ring
seal in overdrive case (Fig. 119).
INSTALLATION
(1) Be sure overdrive unit Alignment Tool 6227-2
is fully seated before moving unit. If tool is not
seated and gear splines rotate out of alignment, over-
drive unit will have to be disassembled in order to
realign splines.
(2) If overdrive piston retainer was not removed
during service and original case gasket is no longer
reusable, prepare new gasket by trimming it.
(3) Cut out old case gasket around piston retainer
with razor knife (Fig. 179).
(4) Use old gasket as template and trim new gas-
ket to fit.
(5) Position new gasket over piston retainer and
on transmission case. Use petroleum jelly to hold
gasket in place if necessary. Do not use any type of
sealer to secure gasket. Use petroleum jelly only.
(6) Install selective spacer on intermediate shaft, if
removed. Spacer goes in groove just rearward of
shaft rear splines (Fig. 180).
(7) Install thrust bearing in overdrive unit sliding
hub. Use petroleum jelly to hold bearing in position.CAUTION: Be sure the shoulder on the inside diam-
eter of the bearing is facing forward.
(8) Verify that splines in overdrive planetary gear
and overrunning clutch hub are aligned with Align-
ment Tool 6227-2. Overdrive unit cannot be installed
if splines are not aligned. If splines have rotated out
of alignment, unit will have to be disassembled to
realign splines.
(9) Carefully slide Alignment Tool 6227-2 out of
overdrive planetary gear and overrunning clutch
splines.
(10) Raise overdrive unit and carefully slide it
straight onto intermediate shaft. Insert park rod into
park lock reaction plug at same time. Avoid tilting
overdrive during installation as this could cause
planetary gear and overrunning clutch splines to
rotate out of alignment. If this occurs, it will be nec-
essary to remove and disassemble overdrive unit to
realign splines.
(11) Work overdrive unit forward on intermediate
shaft until seated against transmission case.
(12) Install bolts attaching overdrive unit to trans-
mission unit. Tighten bolts in diagonal pattern to 34
N´m (25 ft-lbs).
(13) Connect the transmission speed sensor and
overdrive wiring connectors.
(14) Install the transfer case, if equipped.
(15) Align and install rear propeller shaft, if nec-
essary. (Refer to 3 - DIFFERENTIAL & DRIVELINE/
PROPELLER SHAFT/PROPELLER SHAFT -
INSTALLATION)
Fig. 179 Trimming Overdrive Case Gasket
1 - GASKET
2 - SHARP KNIFE
Fig. 180 Intermediate Shaft Selective Spacer
Location
1 - SELECTIVE SPACER
2 - SPACER GROOVE
3 - INTERMEDIATE SHAFT
21 - 234 AUTOMATIC TRANSMISSION - 42REBR/BE
OVERDRIVE UNIT (Continued)

OVERRUNNING CLUTCH
CAM/OVERDRIVE PISTON
RETAINER
DESCRIPTION
The overrunning clutch (Fig. 181) consists of an
inner race, an outer race (or cam), rollers and
springs, and the spring retainer. The number of roll-
ers and springs depends on what transmission and
which overrunning clutch is being dealt with.
OPERATION
As the inner race is rotated in a clockwise direction
(as viewed from the front of the transmission), the
race causes the rollers to roll toward the springs,
causing them to compress against their retainer. The
compression of the springs increases the clearance
between the rollers and cam. This increased clear-
ance between the rollers and cam results in a free-
wheeling condition. When the inner race attempts to
rotate counterclockwise, the action causes the rollers
to roll in the same direction as the race, aided by the
pushing of the springs. As the rollers try to move in
the same direction as the inner race, they are
wedged between the inner and outer races due to the
design of the cam. In this condition, the clutch is
locked and acts as one unit.
DISASSEMBLY
NOTE: To service the overrunning clutch cam and
the overdrive piston retainer, the transmissiongeartrain and the overdrive unit must be removed
from the transmission.
(1) Remove the overdrive piston (Fig. 182).
(2) Remove the overdrive piston retainer bolts.
(3) Remove overdrive piston retainer.
(4) Remove case gasket.
(5) Mark the position of the overrunning clutch
cam in the case (Fig. 183).
(6) Remove the overrunning clutch cam bolts.
(7) Remove the overrunning clutch cam.
Fig. 181 Overrunning Clutch
1 - OUTER RACE (CAM)
2 - ROLLER
3 - SPRING
4 - SPRING RETAINER
5 - INNER RACE (HUB)
Fig. 182 Overdrive Piston Removal
1 - OVERDRIVE CLUTCH PISTON
2 - INTERMEDIATE SHAFT
3 - SELECTIVE SPACER
4 - PISTON RETAINER
Fig. 183 Overrunning Clutch Cam Removal
1 - ALIGN MARKS IDENTIFYING NON-THREADED HOLE IN
CAM AND CASE
2 - OVERRUNNING CLUTCH ASSEMBLY
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 235

REMOVAL
(1) Raise vehicle and position drain pan under
switch.
(2) Disconnect switch wires.
(3) Remove switch from case.
INSTALLATION
(1) Move shift lever to PARK and NEUTRAL posi-
tions. Verify that switch operating lever fingers are
centered in switch opening in case (Fig. 189).
(2) Install new seal on switch and install switch in
case. Tighten switch to 34 N´m (25 ft. lbs.) torque.
(3) Test continuity of new switch with 12V test
lamp.
(4) Connect switch wires and lower vehicle.
(5) Top off transmission fluid level.
PISTONS
DESCRIPTION
There are several sizes and types of pistons used in
an automatic transmission. Some pistons are used to
apply clutches, while others are used to apply bands.
They all have in common the fact that they are
round or circular in shape, located within a smooth
walled cylinder, which is closed at one end and con-
verts fluid pressure into mechanical movement. The
fluid pressure exerted on the piston is contained
within the system through the use of piston rings or
seals.
OPERATION
The principal which makes this operation possible
is known as Pascal's Law. Pascal's Law can be stated
as: ªPressure on a confined fluid is transmitted
equally in all directions and acts with equal force on
equal areas.º
PRESSURE
Pressure (Fig. 190) is nothing more than force
(lbs.) divided by area (in or ft.), or force per unit
area. Given a 100 lb. block and an area of 100 sq. in.
on the floor, the pressure exerted by the block is: 100
lbs. 100 in or 1 pound per square inch, or PSI as it is
commonly referred to.
PRESSURE ON A CONFINED FLUID
Pressure is exerted on a confined fluid (Fig. 191)
by applying a force to some given area in contact
with the fluid. A good example of this is a cylinder
filled with fluid and equipped with a piston that is
closely fitted to the cylinder wall. If a force is applied
to the piston, pressure will be developed in the fluid.
Of course, no pressure will be created if the fluid is
not confined. It will simply ªleakº past the piston.
There must be a resistance to flow in order to create
pressure. Piston sealing is extremely important in
hydraulic operation. Several kinds of seals are used
to accomplish this within a transmission. These
include but are not limited to O-rings, D-rings, lip
seals, sealing rings, or extremely close tolerances
between the piston and the cylinder wall. The force
exerted is downward (gravity), however, the principle
remains the same no matter which direction is taken.
Fig. 189 Park/Neutral Position Switch
1 - NEUTRAL CONTACT
2 - MANUAL LEVER AND SWITCH PLUNGER IN REVERSE
POSITION
3 - PARK CONTACT
4 - SWITCH
Fig. 190 Force and Pressure Relationship
21 - 238 AUTOMATIC TRANSMISSION - 42REBR/BE
PARK/NEUTRAL POSITION SWITCH (Continued)