2001 DODGE RAM Service Repair Manual

oil USB port deactivate airbag navigation update battery location key fob

Page 1873 of 2889

DODGE RAM 2001 Service Repair Manual 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

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)

Page 1874 of 2889

DODGE RAM 2001 Service Repair Manual The pressure created in the fluid is equal to the force
applied, divided by the piston area. If the force is 100
lbs., and the piston area is 10 sq. in., then the pres-
sure created equals 10 PSI. Ano

The pressure created in the fluid is equal to the force
applied, divided by the piston area. If the force is 100
lbs., and the piston area is 10 sq. in., then the pres-
sure created equals 10 PSI. Another interpretation of
Pascal's Law is that regardless of container shape or
size, the pressure will be maintained throughout, as
long as the fluid is confined. In other words, the
pressure in the fluid is the same everywhere within
the container.
FORCE MULTIPLICATION
Using the 10 PSI example used in the illustration
(Fig. 192), a force of 1000 lbs. can be moved with a
force of only 100 lbs. The secret of force multiplica-
tion in hydraulic systems is the total fluid contact
area employed. The illustration, (Fig. 192), shows an
area that is ten times larger than the original area.
The pressure created with the smaller 100 lb. input
is 10 PSI. The concept ªpressure is the same every-
whereº means that the pressure underneath the
larger piston is also 10 PSI. Pressure is equal to the
force applied divided by the contact area. Therefore,
by means of simple algebra, the output force may be
found. This concept is extremely important, as it is
also used in the design and operation of all shift
valves and limiting valves in the valve body, as well
as the pistons, of the transmission, which activate
the clutches and bands. It is nothing more than
using a difference of area to create a difference in
pressure to move an object.
PISTON TRAVEL
The relationship between hydraulic lever and a
mechanical lever is the same. With a mechanical
lever it's a weight-to-distance output rather than a
pressure-to-area output. Using the same forces and
areas as in the previous example, the smaller piston
(Fig. 193) has to move ten times the distance
required to move the larger piston one inch. There-fore, for every inch the larger piston moves, the
smaller piston moves ten inches. This principle is
true in other instances also. A common garage floor
jack is a good example. To raise a car weighing 2000
lbs., an effort of only 100 lbs. may be required. For
every inch the car moves upward, the input piston at
the jack handle must move 20 inches downward.
Fig. 191 Pressure on a Confined Fluid
Fig. 192 Force Multiplication
Fig. 193 Piston Travel
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 239
PISTONS (Continued)

Page 1875 of 2889

DODGE RAM 2001 Service Repair Manual PLANETARY GEARTRAIN/
OUTPUT SHAFT
DESCRIPTION
The planetary gearsets (Fig. 194) are designated as
the front, rear, and overdrive planetary gear assem-
blies and located in such order. A simple planeta

Page 1876 of 2889

DODGE RAM 2001 Service Repair Manual (4) Remove tabbed thrust washer and tabbed
thrust plate from hub of front annulus (Fig. 197).
(5) Separate front annulus and planetary gears
(Fig. 197).
(6) Remove front planetary gear front thrust
wa

(4) Remove tabbed thrust washer and tabbed
thrust plate from hub of front annulus (Fig. 197).
(5) Separate front annulus and planetary gears
(Fig. 197).
(6) Remove front planetary gear front thrust
washer from annulus gear hub.
(7) Separate and remove driving shell, rear plane-
tary and rear annulus from output shaft (Fig. 198).
(8) Remove front planetary rear thrust washer
from driving shell.
(9) Remove tabbed thrust washers from rear plan-
etary gear.
(10) Remove lock ring that retains sun gear in
driving shell. Then remove sun gear, spacer and
thrust plates.
INSPECTION
Check sun gear and driving shell condition.
Replace the gear if damaged or if the bushings are
scored or worn. The bushings are not serviceable.
Replace the driving shell if worn, cracked or dam-
aged.
Replace planetary gear sets if gears, pinion pins, or
carrier are damaged in any way. Replace the annulus
gears and supports if either component is worn or
damaged.
Inspect the geartrain spacers, thrust plates, snap-
rings, and thrust washers. Replace any of these parts
that are worn, distorted or damaged. Do not attempt
to reuse these parts.
The planetary gear thrust washers are different
sizes. The large diameter washers go on the front
planetary and the smaller washers go on the rear
planetary. All the washers have four locating tabs onthem. These tabs fit in the holes or slots provided in
each planetary gear.
Inspect the output shaft carefully. Pay particular
attention to the machined bushing/bearing surfaces
on the shaft and the governor valve shaft bore at the
shaft rear.
Replace the output shaft if the machined surfaces
are scored, pitted, or damaged in any way. Also
replace the shaft if the splines are damaged, or
exhibits cracks at any location (especially at the gov-
ernor valve shaft bore).
The annulus gears can be removed from their sup-
ports if necessary. Just remove the snap-rings and
separate the two parts when replacement is neces-
sary. In addition, the annulus gear bushings can be
replaced if severely worn, or scored. However it is not
necessary to replace the bushings if they only exhibit
normal wear. Check bushing fit on the output shaft
to be sure.
ASSEMBLY
(1) Lubricate output shaft and planetary compo-
nents with transmission fluid. Use petroleum jelly to
lubricate and hold thrust washers and plates in posi-
tion.
(2) Assemble rear annulus gear and support if dis-
assembled. Be sure support snap-ring is seated and
that shoulder-side of support faces rearward (Fig.
199).
(3) Install rear thrust washer on rear planetary
gear. Use enough petroleum jelly to hold washer in
place. Also be sure all four washer tabs are properly
engaged in gear slots.
(4) Install rear annulus over and onto rear plane-
tary gear (Fig. 199).
Fig. 197 Front Planetary And Annulus
Gear Disassembly
1 - FRONT ANNULUS
2 - THRUST WASHER
3 - THRUST PLATE
4 - FRONT THRUST WASHER
5 - FRONT PLANETARY
Fig. 198 Removing Driving Shell, Rear Planetary
And Rear Annulus
1 - REAR ANNULUS
2 - REAR PLANETARY
3 - DRIVING SHELL
4 - OUTPUT SHAFT
BR/BEAUTOMATIC TRANSMISSION - 42RE 21 - 241
PLANETARY GEARTRAIN/OUTPUT SHAFT (Continued)

Page 1877 of 2889

DODGE RAM 2001 Service Repair Manual (5) Install assembled rear planetary and annulus
gear on output shaft (Fig. 200). Verify that assembly
is fully seated on shaft.
(6) Install front thrust washer on rear planetary
gear (Fig. 201). Use

Page 1878 of 2889

DODGE RAM 2001 Service Repair Manual (9) Hold sun gear in place and install thrust plate
over sun gear at rear of driving shell (Fig. 204).
(10) Position wood block on bench and support sun
gear on block (Fig. 205). This makes it easier

Page 1879 of 2889

DODGE RAM 2001 Service Repair Manual (13) Install rear thrust washer on front planetary
gear (Fig. 208). Use enough petroleum jelly to hold
washer in place and be sure all four washer tabs are
seated.
(14) Install front planetary gear on

Page 1880 of 2889

DODGE RAM 2001 Service Repair Manual (20) Install front annulus snap-ring (Fig. 212). Use
snap-ring pliers to avoid distorting ring during
installation. Also be sure ring is fully seated.
(21) Install planetary selective snap-ring with
s

Load next 8 pages

Page: < prev 1-10 ... 1841-1848 1849-1856 1857-1864 1865-1872 1873-1880 1881-1888 1889-1896 1897-1904 1905-1912 ... 2896 next >

windshield wipers sport mode rear entertainment wheel alignment gas tank size warning light